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hcbph Need some electrical smarts.
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I know enough about a DVOM to be dangerous, so I'm looking for some help to determine if I'm on the right path or not.

Here's the background. I replaced the battery in my 86 because the one I had in it was a leftover from the kids car, under size and looks to be almost 5 years old and run down pretty much dead. Put it in last saturday, I'd put a charger on it at 2 amps and green light came on indicating it was fully charged. Car started and ran. Went out sunday and everything was dead. I thought maybe I had the charger on the wrong scale and it wasn't actually charged, so I charged it all sunday unhooked from the car. The charger has an automatic cutoff and disconnected when it showed fully charged. Car started and ran fine. IIRC the dash voltmeter showed 13.2v while driving it around saturday.

Here's where the help is needed. I've cleaned up the ground on the drivers side kickpanel, moved a power lead for the speedometer converter from a battery lug to that junction block behind the battery. While I was doing that, I checked all the wiring I could get to for any bare spots etc, didn't find any but covered a couple anyway. I also put some heat sleeves on the plug wires.

Tonight I was putting a temporary battery cutoff on the battery negative cable where it hooks up to the battery (positive cable was hooked up) and touched the wrench to metal strip on the panel you remove to take out the battery while putting the adapter on the negative lug on the battery and got arcing. The negative cable had yet to be connected to the cutoff, it was not touching anything at that time.

With the battery cable disconnected, I noticed I had voltage on the engine. With the voltmeter shown, turn the switch counter clockwise to 20, show 13 (volts I assume) with doors closed etc, nothing on going from the alternator bracket to the negative battery terminal with the cable disconnected. I pulled every fuse in the main fuse panel one at a time, always got 13v check each one at a time.
Switching to the amp setting, every one from 200u to 200m showed nothing. If i moved the meter cable to the 10A DC plug and switched to the white 10A setting, I got a 19.x. Touched the negative on the battery and definitely got an arc when I touched the alternator bracket.

Is that saying I've got 19 amps going through the car with everything off? I can't get under the car right now but to me logically it seems most likely something directly off the postive battery cable before it goes to anything including the fuses. Does that make sense, or is there something I'm missing?

I did a topside once over on the engine and checked every wire I could get my hands on, I found none burnt, cracked or touching anything they shouldn't. About the only one I have not gotten to is the positive battery cable, mainly because it looks ok to the point it's at the back of the engine and haven't yet gotten it where I can raise it enough to get under there.

Apprecate any info or ideas of where to look.

Thanks

Paul

One more thing, I'd been using that battery cutoff for some time, but was planning on upgrading to a better unit. This could have been going on for some time but because I was breaking the connection to the negative cable when not in use it wasn't apparent till now. It's this one: http://www.summitracing.com/parts/mor-74104/overview/


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Posted on: 2016/4/5 1:19
Edited by hcbph on 2016/4/5 1:50:30
Edited by hcbph on 2016/4/5 1:53:01
Edited by hcbph on 2016/4/5 1:58:37
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Matatk Re: Need some electrical smarts.
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Since you said you had a transmission swap done, it's possible something was pinched. Or that could be a dead avenue. But something to consider.

From what I read, you pulled all of the fuses and there was still voltage at the ground point where you were reading it?
Posted on: 2016/4/5 3:12
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hcbph Re: Need some electrical smarts.
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The transmission was done before I bought the car in 2013. All the dash and electrical seems to work ok as does the tranny. The only thing I've had any issues with is the ABS light occassionally comes on which I haven't addressed yet and the interior light relay is out.

Yes I pulled the fuses in the main fuse panel one at a time, then checking the engine to the negative battery point. I showed voltage still present every time.

Am I interpreting the DVOM readings correctly? I would think that if there was a direct to ground short, I'd see something. Thinking on this later, is it possible to have something like the alternator short internally where the engine is electrically hot yet everything still works? With the cables hooked up but not starting the car, I didn't find any that got hot.
I can touch the positive lead of voltmeter to the alternator bracket, TPI, cruise control cable, etc and the negative to the battery post (with the positive cable only connected) and show current flowing. Either I didn't find a good spot or not but didn't get any indication of current from the firewall to battery.

That juice has to be coming from somewhere, but where to start looking?
Posted on: 2016/4/5 9:55
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Matatk Re: Need some electrical smarts.
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19 amps would be a lot. I would pull the power cable and put the dvom between the battery and the cable with the doors closed and interior lights/timer off and check the draw that way. You should have something like .35 milliamps as a draw. Pull fuses until it drops.

Here's an example of a way to check using a test light, same idea:

https://youtu.be/9wLrTjeb9TY
Posted on: 2016/4/5 15:37
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BillH Re: Need some electrical smarts.
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Quote:

hcbph wrote:

One more thing, I'd been using that battery cutoff for some time, but was planning on upgrading to a better unit. This could have been going on for some time but because I was breaking the connection to the negative cable when not in use it wasn't apparent till now. It's this one: http://www.summitracing.com/parts/mor-74104/overview/



If you read the discussions by guys with classic cars (C1's and C2's etc.) you'll find 25% of them never have problems with these cutoffs, the rest do.

I've seen a bunch of them thrown away by guys I know.

There are much better cut off switches, costs more and you'll have to fab up a short battery cable but the good ones will give you zero problems.
Posted on: 2016/4/5 16:16
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bogus Re: Need some electrical smarts.
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19 volt drain?

Time to start pulling each wire off the battery block and check the fusable link lines... something is sucking it dry - and fast.

Posted on: 2016/4/6 0:21
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hcbph Re: Need some electrical smarts.
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Quote:

Matatk wrote:
19 amps would be a lot. I would pull the power cable and put the dvom between the battery and the cable with the doors closed and interior lights/timer off and check the draw that way. You should have something like .35 milliamps as a draw. Pull fuses until it drops.

Here's an example of a way to check using a test light, same idea:

https://youtu.be/9wLrTjeb9TY


I'll have to try that out, but may be the 2d on the list to do.

Quote:

BillH wrote:
If you read the discussions by guys with classic cars (C1's and C2's etc.) you'll find 25% of them never have problems with these cutoffs, the rest do.

I've seen a bunch of them thrown away by guys I know.

There are much better cut off switches, costs more and you'll have to fab up a short battery cable but the good ones will give you zero problems.

I don't think it's 19 volts, 13 volts 19 amps based on the meter readings if I'm reading the meter right.

I have to agree. This one is only rated at 100 amp and is a little clumky to operate, the one I plan to replace it with I bought last year is good to 250 amps and has a rotary handle to make or break the connection. I was looking into the cables I'd need to mount it once I'm ready to do it along with how I want to mount it.

Thing is, I've already tested with all the fuses pulled from the main panel (1 at a time), there's still current present if you check from the engine brackets, TPI etc to the battery negative post with the negative cable unhooked. Firewall still shows nothing if check from the firewall to the negative battery post with the negative cable unhooked.

Remember in all the testing I did, the negative battery was unhooked, I touched either the alternator bracket or the TPI runner with the red lead to the voltmeter and the negative to the negative post on the battery, positive cable hooked up with all electrical off. I was not touching any wiring, only the physical engine parts then the firewall.

Thinking through this, the short has to be under the hood before it ever gets to the fuse panel. I'm thinking my next step is to remove the wires from that electrical junction behind the battery one at a time and see if it drops. If it does, I then at least know which wire to target and trace.

Does that make sense to anyone other than me?

Appreciate all the ideas, keep them coming.

Paul

PS, here's the the switch I was putting back on for along with the one I plan to replace it with. The blue piece is a plastic tab I made to fit under the bolt when the battery is disconnected. You can snug the bolt down but it won't complete the circuit till it's removed.
[URL=http://s162.photobucket.com/user/hcbph/media/Corvette/Misc/IM002029_zpsvflwyhbz.jpg.html]Resized Image[/URL]
Posted on: 2016/4/6 0:26
Edited by hcbph on 2016/4/6 1:14:16
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BillH Re: Need some electrical smarts.
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The switch from Summit is the way to go.

You are not putting the knob back on are you?
Posted on: 2016/4/6 13:38
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BrianCunningham Re: Need some electrical smarts.
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Early C4 have an issue with wire degradation
Posted on: 2016/4/6 23:37
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hcbph Re: Need some electrical smarts.
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Quote:

BrianCunningham wrote:
Early C4 have an issue with wire degradation


That's kind of what it's looking like. I pulled the fuse out of the Dakota adapter for the speedometer converter, kind of hoping that's where it's at. Other than the fuse disintegrating in my hand, wasn't the cause.

Going to have to start pulling wires off that junction (first thing I plan to try) and see if I can identify which one of them is the culprit, assuming one is the root cause.

On the question of the lighter weight battery disconnect, yes I'm planning on using it once I have this issue fixed until such time as I can get the cables to replace it with that Summit cutoff I already have.

Unfortunately I don't think I'll have time to get back to it before this weekend :-(

I'll keep you posted.

Paul
Posted on: 2016/4/7 0:15
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hcbph Re: Need some electrical smarts.
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I was thinking on this more later last night. I would think if it's actually getting 19 amps through whatever is shorting, if it was one of those hot wires off the junction the fusible link would blow. At least I thought they all had one but haven't checked it out yet to confirm. About the only thing I can think of that isn't likely fused in some way is the main positive battery cable from the battery to the starter. Especially where it goes between the motor and firewall, that would be a good place to have worn insulation and not be visible.

Does that make sense?

Still planning on doing the methodical removal from the junction first but suspecting that may be what I find. Especially if they're all off, I plan to pull the other end of that main cable off the starter and see if it's still electrically hot. Not looking forward to it, but I would think the positive battery cable would be easier to get to, assuming I can get under the car.

Just some thoughts.
Posted on: 2016/4/7 12:40
Edited by hcbph on 2016/4/7 13:02:16
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donhall Re: Need some electrical smarts.
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Paul, are you measuring amps correctly?

Here is a tutorial on the procedure:

http://www.wikihow.com/Measure-Amperage
Posted on: 2016/4/7 14:06
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hcbph Re: Need some electrical smarts.
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Quote:

donhall wrote:
Paul, are you measuring amps correctly?

Here is a tutorial on the procedure:

http://www.wikihow.com/Measure-Amperage


According to that webpage, I was doing it right, but it doesn't tell how to interpret the readings.

With the meter dial set to the 10A setting under amps, the red cable plugged into the 10A DC plug port, meter ground wire plugged into common port on the meter I get a reading of 19.xx where the decimal floats a little between .04 and maybe .85 when going from the alternator bracket to the negative post on the battery (it's a side mount but I don't know what else to call it) and the negative battery cable disconnected. I can't find anything that tells what those meter readings mean, I'm guessing based on the value and the amount of arcing I get when touching the meter lead to the alternator bracket, it's the 19 amps but don't know if that's right or not.

Car Ground cable disconnected completely from the battery, positive car battery cable hooked up to the battery and the meter negative lead touching the negative battery post. I get one heck of an arc when touching the red meter lead to the alternator bracket engine. I also got a single ding at times like if you open the door with the engine off and the key in the ignition or the lights were still on as soon as you touch the alternator bracket with the meter positive lead.

I just checked again, if I go against the upper A arm on the drivers side front, I get 17.xx, I also get arcing if i touch the frame but not off the firewall. Now this may or may not be accurate. I'm partially deaf and at least one time I think I hear something run (like an electrical motor) for 3 or 4 seconds. Reminded me of the sound when the radio antenna extends but fairly sure it was near the firewall and the antenna did not extend.
Posted on: 2016/4/7 23:30
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donhall Re: Need some electrical smarts.
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Paul, try this......

1. Connect ground cable to negative batt post.
2. Disconnect positive cable from positive batt post.
3. Set meter according to link provided for amp reading.
4. Position probes inline with one probe touching positive cable,
and one probe touching positive batt post.

Amp reading?
Posted on: 2016/4/8 0:02
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hcbph Re: Need some electrical smarts.
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Quote:

donhall wrote:
Paul, try this......

1. Connect ground cable to negative batt post.
2. Disconnect positive cable from positive batt post.
3. Set meter according to link provided for amp reading.
4. Position probes inline with one probe touching positive cable,
and one probe touching positive batt post.

Amp reading?


Black meter lead to the positive battery cable, red lead to the the positive post on the battery. Negative battery cable hooked up to the battery. Meter on the 10A setting, red lead in the 10A dc spot on the meter and the black to common.
Reading: varied from 19.7 - 19.9 but I was having trouble holding them absolutely tight and not moving. Kind of sounded like there was a thunk through the radio speaker (inside the car somewhere) each time I pressed the lead to the battery post. Everything was closed up including the windows so can't be absolutely sure.
Posted on: 2016/4/8 0:35
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donhall Re: Need some electrical smarts.
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Difficult to believe that 19+ amps is displayed.
Nothing but the starter motor draws such excessive amps.

Measuring amps should not cause any 'noise', or arcing.

It is possible the meter may be faulty ..... have access to a second meter?
The meter is fused, so it should be protected, but..........


Using the same set-up you described:

Make sure you have the probes solidly attached (not finger tight) to the pos cable, and the pos batt post.

Pull one fuse at a time, and note any difference in the amp reading.
When the amp reading drops, you will have identified the problem circuit.

Unfortunately, a fuse may protect more than one circuit, so trouble shooting
becomes more difficult.

Posted on: 2016/4/8 1:22
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hcbph Re: Need some electrical smarts.
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Don

I've got 3 or 4 of those free HF units, I've tried one of those with the same results going from the alt bracket to ground part of the test.
I've already tried pulling the fuses out of the fuse panel one at a time, no change in the voltage readings from the alt bracket to battery ground.
If I have the time, I'm thinking I'm going to start taking thing apart this weekend starting at that fuse junction behind the battery. Everything I've tried (to me) seems to indicate a dead short and with that much juice I haven't noticed one fuse big enough to handle that much without blowing except for the one on the signal converter for the speedometer and I've pulled that one too to insure it wasn't the cause.

I keep coming back to it's got to be under the hood, going to ground and before any fuses. The only one I can think of that matches that description is the battery to starter or battery to that wire junction behind the battery.

Thing is, I don't smell anything, don't see anything obviously wrong, nothing.

I'll see what this weekend brings.
Posted on: 2016/4/8 2:05
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donhall Re: Need some electrical smarts.
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Paul, I sent your thread to a EE on another forum. He is a savvy guy.
Will let you know if/when he responds.
Posted on: 2016/4/8 2:36
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hcbph Re: Need some electrical smarts.
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Quote:

donhall wrote:
Paul, I sent your thread to a EE on another forum. He is a savvy guy.
Will let you know if/when he responds.


Appreciate it. Here's hoping.
Posted on: 2016/4/8 9:51
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Schrade Re: Need some electrical smarts.
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19 AMPS is a LOT. Perhaps the reading is off 2 decimal places for meter setting?

Yay or nay, I would disconnect the battery NOW, and LEAVE IT, until you can start testing INDIVIDUAL circuits.

19 Amps (or less, depending on what's in the car - wiring-wise), will start a fire in SHORT ORDER.
Posted on: 2016/4/8 11:44
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donhall Re: Need some electrical smarts.
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Paul, the following message is the response received from my EE friend:

"Ammeters don't lie. Some electrical circuit in the car is conducting 19 amps from the positive terminal to ground and is the reason for the spark on the wrench when it touched ground. The wrench must have touched the neg bat terminal, AND then ground (the metal hold down bracket).

Here is a situation where I love my clamp-on DC ammeter which allows you to tell which wire is conducting leakage current without the dang bother of disconnecting each wire and using your DVOM!!!

I bought a Sears clamp on dc meter with a discount coupon about a year ago for about $40 ($60 without the coupon, and the lowest cost clamp dc meter I know of).

One circuit that I would look at first is the alternator to battery connection. This connection has a fusible link, not an unpluggable fuse and 19 amps won't blow the fusible link. The alternator could have a blown rectifier diode and with the engine running the alternator could easily supply both battery charging current and 19 amps to ground through the blown rectifier. I would unbolt the large red wire on the alternator first, disconnecting the bat ground, and then reconnect the bat ground, and measure the current flowing between the large red wire, and the alternator terminal (engine off). If that isn't it, then you have to measure the current on every wire the bat positive term is connected to.

The second wire I would test would be the starter motor large wire, if it isn't fused.

Do the same procedure as the alternator wire.

Third, would be the starter solenoid wire, if it too, is not fused.

Owner has pulled all fuses, and leakage current still exists.

Hope this helps."
Posted on: 2016/4/8 13:10
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hcbph Re: Need some electrical smarts.
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Thanks much, every bit helps.

I wish there was something that explained what the meter reading meant. Like 19.x on the 10 amp setting, is that 19 amps or 1.9x10 or what.

I'm no electrical wizard, I mostly use my meter for checking ohms, actually to see if there is a complete circuit or not. Much beyond that and I'm in trouble.

I'm hoping I can do some of those tests this weekend too. I had a job come in from a customer that I need to get on too. Have to pay the bills [doesn't everyone :-) ]

I'll post when I find out something (hopefully)

Paul
Posted on: 2016/4/8 13:18
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donhall Re: Need some electrical smarts.
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Quote:

hcbph wrote:
Thanks much, every bit helps.

I wish there was something that explained what the meter reading meant. Like 19.x on the 10 amp setting, is that 19 amps or 1.9x10 or what?

Paul


I will ask about the amp reading, and report back.

don
Posted on: 2016/4/8 13:23
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donhall Re: Need some electrical smarts.
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Paul, an answer to your amp question(s):

"The instruction manual should say what this reading means. I suspect that it means the current is higher than 10 amps. Better meters have the 10 amp range fused, but not all. If you exceed 10 amps, and depending on how much, you could burn out the current sense resistor, which is usually 0.1 ohms."

Paul, your electrical situation may be above your pay-grade (not an insult).
You might consider contacting an auto-electric shop.
Posted on: 2016/4/8 14:52
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donhall Re: Need some electrical smarts.
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Paul, more info from my EE that may help:

"If he has pulled all the fuses, then there are only three circuits he needs to measure current in. Alternator, starter motor, and starter solenoid. I don't have a schematic for his car, so there might be more circuits that don't have a removeable fuse."
Posted on: 2016/4/8 17:34
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hcbph Re: Need some electrical smarts.
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Quote:

donhall wrote:
Paul, your electrical situation may be above your pay-grade (not an insult).
You might consider contacting an auto-electric shop.


No offense taken. My mechanic is backed up now and said it would be some time before he could get to it (I did ask already), so I'm trying to see if I can track it down in the mean time.

This is my 'retirement' project. I'm planning the day I can actually retire and drive as much of the original Route 66 as I can get on. I want to be as familiar and knowledgeable on the car I can just in case. It's not like I 'have' to have it running on any particular day, other than I'm planning a trip the end of August so it needs to be fixed by then. Other than that, it's just fun driving.

I'm not the fastest or most limber since being broadsided by a truck a number of years ago, but I actually feel good working on the Vette. That's something I couldn't do for a lot of years and had to always hire out even little tasks because it was too painful or impossible for me to do. I guess you could say I'm playing catch-up, doing some of that stuff I couldn't do for so many years.
Posted on: 2016/4/8 18:27
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bogus Re: Need some electrical smarts.
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Quote:

hcbph wrote:
Quote:

donhall wrote:
Paul, try this......

1. Connect ground cable to negative batt post.
2. Disconnect positive cable from positive batt post.
3. Set meter according to link provided for amp reading.
4. Position probes inline with one probe touching positive cable,
and one probe touching positive batt post.

Amp reading?


Black meter lead to the positive battery cable, red lead to the the positive post on the battery. Negative battery cable hooked up to the battery. Meter on the 10A setting, red lead in the 10A dc spot on the meter and the black to common.
Reading: varied from 19.7 - 19.9 but I was having trouble holding them absolutely tight and not moving. Kind of sounded like there was a thunk through the radio speaker (inside the car somewhere) each time I pressed the lead to the battery post. Everything was closed up including the windows so can't be absolutely sure.


Check the relay that fires off the Bose amps, assuming you have Bose... A thing in my brain is telling me that relay fails...

Posted on: 2016/4/8 19:31
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hcbph Re: Need some electrical smarts.
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Quote:

donhall wrote:

Check the relay that fires off the Bose amps, assuming you have Bose... A thing in my brain is telling me that relay fails...



If there's a relay remaining, I'll have to dig into the FSM and see if I can locate where that's at if it's still in the car.

Other than general maintenance items, all the major others were done before I bought the car:
Bose system replaced with a Sony Radio/CD, no external amp.
4+3 tranny was replaced with a Tremec 5 speed, a Dakota Digital converter to drive the speedometer.
I put a VATs Bypass plug on it along with bypassed the clutch must-be-depressed switch the first month after I bought it in 2013. Neither has caused a problem before but will be rechecking to insure nothing has changed.

Getting my plan put together to start execution this weekend. Hopefully it won't take long to nail it down but if it does, so be it.
Posted on: 2016/4/8 22:48
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hcbph Re: Need some electrical smarts.
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I still have to reassemble a couple of things, but I think I found the culprit circuit. Here's what I did to track it down.

I started pulling the wires off that junction between the battery and firewall one at a time. I jumpered from the engine to each wire to see if there was a circuit or not via an OHM meter, one proved to be completing a circuit (2 wires off a common eyelet). Wire looked to go into the firewall and maybe to the cooling fans but wasn't sure, so went back to the cab to check further.

I have the car parked so the passenger door won't open fully so the fuse panel is hard to see and there's no diagram on the back side of the fusebox cover. I found a diagram online to fill in the holes in what went where.
What I thought were relays turned out to be circuit breakers, and the 4th one down from the top is for the power door locks and electric seat. I hadn't pulled the breakers before, only the fuses and when I pulled that one for the locks and seats the short immediately showed gone.

I used jumper cables to connect the cables in the car to the battery (everything is out now) and I no longer show voltage or amps coming off the engine. I also doublechecked with the ohm meter, looks good.

Logically the locks are hot all the time and it's very possible the short is in the doors or the wiring to the doors. The seat is already set for me and I've only used the power locks when the wife was going along. I can live without them for now. I'm planning on changing the weather stripping on the doors later and I'll look into them further at that time.

Once I have it back together, I'll recheck and confirm whether it's all good or not. Got my finger crossed.
Posted on: 2016/4/9 17:54
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donhall Re: Need some electrical smarts.
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Good luck, Paul.

I sent your post to my EE friend with a note suggesting he join the C4Guru
group, and post directly to your thread (and others).

Joe goes by jfb on the other forum. He is a prolific poster, and would be
a huge asset to Andy's creation.
Posted on: 2016/4/9 18:11
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hcbph Re: Need some electrical smarts.
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Quote:

donhall wrote:
Good luck, Paul.

I sent your post to my EE friend with a note suggesting he join the C4Guru
group, and post directly to your thread (and others).

Joe goes by jfb on the other forum. He is a prolific poster, and would be
a huge asset to Andy's creation.


Please encourage him to join. I consider myself fairly mechanically inclined and can even do some basic electrical work. I know when I'm in over my head and stop before aggrevating a problem.

Problem for me is as each generation of car has arrived, my ability to diagnose and figure out issues has gone down, especially the electronic ones. To have someone knowledgable and willing to share that info would be a tremendous asset to the forum.

I share what little I can and want to learn more when I can and it's through stuff like this I learn. For me, asking questions and help is how I learn.

Paul

P.S. have the car back together, I think all is good as far as I can tell.
Posted on: 2016/4/9 19:43
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donhall Re: Need some electrical smarts.
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Paul, Joe's response to your post:

Glad to hear you found the leakage current! You did the right thing. A clamp on D.C. ammeter would have made that job easier :D. I owned a C4, an 87 for 26 years and finally my mechanic said he didn't want to see it again and it had 250,258 miles on it and I drove it everyday. It needed a fuel pump and the OD overhauled for the 3rd time so I gave it to St. Vincent dePaul. I now own an 02 ZO6.
Posted on: 2016/4/9 23:35
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hcbph Re: Need some electrical smarts.
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Tell Joe thanks, as well as thanks to everyone here for their help.

Ask Joe if he knows of any instructions online on how to use a clamp on D.C. Ammeter. I'm assuming that's a clamp on DVOM, but other than general info in the owners manual I found online (got my interest the other day on the one reference), it didn't give any indications on how to use it. That's one of the main problems I have. You can buy all the tools you can afford but if you don't know how to use them properly, it's wasted money.

Paul

PS - while in there, I'm thinking about putting a relay on the Dakota Digital convertor for the speedometer. It was and is currently wired hot to the battery. I'm thinking I want to put a relay on it so it's only energized when the key is on. I think I found the relay on Ebay but next is I'll have to spend some time with the FSM and see if I can figure out a good point to connect the switching part of the relay to under the hood that's only energized when the key is on.
Posted on: 2016/4/10 2:16
Edited by hcbph on 2016/4/10 2:32:20
Edited by hcbph on 2016/4/10 2:34:35
Edited by hcbph on 2016/4/10 2:36:28
Edited by hcbph on 2016/4/10 2:37:02
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donhall Re: Need some electrical smarts.
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Paul, here is Joe's reply re the clamp-on DC ammeter, and your relay question:

"A clamp on DC meter is easy to use, you squeeze the middle of the DVOM which opens the jaws and close the jaws around the wire you want to know the value of the current flowing in it. No different than a clamp on AC ammeter.

A relay shouldn't be necessary to turn on your dash because you can switch the power to the dash to one of the switched power wires from the ignition switch."



My basic explanation for the DC clamp-on ammeter: instead of disconnecting the batt cable from the batt post, and placing the meter probes in series (in-line) with the cable and post, you just attach the DC ammeter to the wire you wish to measure current flow. Simple, no disconnection of cables/wires to determine amps.

Just ensure the meter is for DC current. Harbor Freight does not sell DC ammeters, just AC ammeters, and AC/DC volt meters.

Sears has an AC/DC ammeter listed for $60.....not a recommendation, just FYI.
Posted on: 2016/4/10 11:51
Edited by donhall on 2016/4/10 12:42:42
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hcbph Re: Need some electrical smarts.
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Don

Spent most of the freetime today looking online and at Sears. Finally found one at Amazon. There's one 'maybe' at Sears but it's $100. I figure based on the info so far, it makes sense to get one ahead of time for when I do open the door up.

I appreciate everyone's help finding this issue. Until my back started acting up, spent the day finishing installing the stainsteel straps, getting one last plug wire where it should be and found one possible tool I may pick up and try. One of those niche things so we'll see if after alittle more looking if it's worth recommending or not.

Thanks again.

Paul
Posted on: 2016/4/10 22:29
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donhall Re: Need some electrical smarts.
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This is the Sears $60 meter:

Craftsman Digital Clamp-On Ammeter
Description Item # 03482369000P Model # 82369
Posted on: 2016/4/10 23:28
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hcbph Re: Need some electrical smarts.
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Thanks. I looked at one (I think) at Sears yesterday that looked like that one but did not reference reading DC Amps via the clamp on.
Posted on: 2016/4/11 9:35
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hcbph Re: Need some electrical smarts.
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Found a new 'toy' and found the root problem. A little something that you can plug a fuse in from the panel and see how many amps it's pulling and it was only about $12. So I plugged it into that slot where the breaker was and used a 30 amp fuse in the tool. 0 amps - made no sense. Then it dawned on me, I'd had alot of tools etc in the car and some where on the console. Well I'd packed them up so they weren't there now. Pushing down on the electric seat adjuster - 19 amps, power locks - 7 amps. Pretty sure I had to have some stuff on the box of altoids I had in that well and likely were pushing down on the switch.

I admit when I do something stupid, and this was a self-induced stupid problem that never should have occurred.

Attach file:



jpg  IM002039.JPG (84.71 KB)
21158_5713af5af091a.jpg 480X640 px
Posted on: 2016/4/17 15:48
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donhall Re: Need some electrical smarts.
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Good fix, and find (tool), Paul. I see that tool on eBay for $12.99.
Will add to inventory, and hope I never have to use it.
Thanks.



MY ERROR........ EBAY TOOL ON EBAY IS NOT THE SAME TOOL POSTED BY
hcbph.
Posted on: 2016/4/17 16:11
Edited by donhall on 2016/4/17 17:00:31
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hcbph Re: Need some electrical smarts.
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Now if you happen to have a HF close by, use the 20% off and it brings it to 12 or 13 plus you can get their freebee if it's of use to you (I picked up another set of screw drivers) though what I got I already have at least 2 or 3 on the wall and another one in the tool bucket.

Had another thought, think people would like a tools and tips thread? Something where if you have what feel is a good tool or tip, and can share it with others? I have a few that might be useful to others and I know you guys likely have alot more than that.
Posted on: 2016/4/17 16:36
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donhall Re: Need some electrical smarts.
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Quote:

hcbph wrote:

Had another thought, think people would like a tools and tips thread? Something where if you have what feel is a good tool or tip, and can share it with others? I have a few that might be useful to others and I know you guys likely have alot more than that.


Maybe if BillH gets around to reading your post, he may respond to your proposal.
Andy is too busy repairing his rear-ended vette.
Posted on: 2016/4/17 16:48
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hcbph Re: Need some electrical smarts.
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I was thinking more in line with a new thread in here where people could do their 'pay it forward' stuff. Tell others of tools or tips that work out for someone.
Posted on: 2016/4/17 18:38
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Matatk Re: Need some electrical smarts.
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Glad you found it!
Posted on: 2016/4/18 1:03
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