Low voltage indication... [Forums - C4 Technical]

C4 Technical > Low voltage indication...
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Schrade	Low voltage indication...	#1
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Where in FSM is ALDL Schematic? Battery is new, DVM indicates 12.9 V across terminals. Tech 1 shows 11.2 volts, motor off. Motor running shows 13+ V. Nard to tell exactly what gauge is reading... ALDL Ground is good - DVM showed full B+ power in ALDL Terminal A; Ground Connector. None of the ALDL Terminals is B+, that I see... Handheld for tranny control module ALSO shows 11.2V, motor off, and full B+, motor running. Help?
	Posted on: 2016/4/20 20:04
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Schrade	Re: Low voltage indication...	#2
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	I guess the question is, on what channel in ALDL is the B+ signal coming in on?
	Posted on: 2016/4/20 22:46
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bogus	Re: Low voltage indication...	#3
Grand Imperial Pooh-Bah San Pedro, CA 20859 Posts Member since: 2005/9/7 0:00	I know there is a break out... where? I can't tell you off hand. Check the electrical diagnosis section.
	Posted on: 2016/4/22 0:16
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Matatk	Re: Low voltage indication...	#4
Webmaster SW Chicago Burbs 22805 Posts Member since: 2008/1/7 0:00	I believe there is a reading for the fuel pump voltage, but I don't have my manual out. Is that what you're seeing?
	Posted on: 2016/4/22 11:59
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Schrade	Re: Low voltage indication...	#5
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	No - not fuel pump voltage, I don't think. THat's a separate read on Tech 1. Both Tech 1, and handheld programmer for tranny control module are showing low voltage 11.2V. Both plug in to cigarette lighter, but both are NOT reading Voltage @ cigarette lighter (although THAT could also be 11.2V...) I cannot find wiring schematic for ALDL Leads in 8A.
	Posted on: 2016/4/24 20:26
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Matatk	Re: Low voltage indication...	#6
Webmaster SW Chicago Burbs 22805 Posts Member since: 2008/1/7 0:00	ALDL doesn't have power until OBDII. Check the cigarette lighter with a DVOM. They get crusty in there and it limits the voltage.
	Posted on: 2016/4/25 10:39
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Schrade	Re: Low voltage indication...	#7
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	This one is NOT solved yet... The cig lighter harness AND connectors AND Lighter contacts are CLEANED and Di-electric greased. Is there a voltage loss with Ignition off? Again, motor RUNNING gives FULL B+ Power readings on Tech 1, and on Tranny Handheld Controller, Both of which are sourced at cig lighter. Does this show something actually wrong??? Shouldn't readings be same; motor off, and motor running? Daryll? Quote: Matatk wrote: ALDL doesn't have power until OBDII. Check the cigarette lighter with a DVOM. They get crusty in there and it limits the voltage.
	Posted on: 2016/7/10 13:28
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bogus	Re: Low voltage indication...	#8
Grand Imperial Pooh-Bah San Pedro, CA 20859 Posts Member since: 2005/9/7 0:00	voltage off, should be about 13v. when running, about 14v. 12v is merely nominal. Check the battery terminals. They get old and corrode. Also check the cables from the battery; the corrosion can easily track up the cable, increasing resistance. I replaced both my cables a few years ago, the OEM ones were junk by then.
	Posted on: 2016/7/10 20:33
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GOLDCYLON	Re: Low voltage indication...	#9
Guru Newb Peoria, Arizona 23 Posts Member since: 2012/1/30 20:32	I think 12.6 V is normal dry battery voltage on the rack. So in other words not running that's normal voltage. While running it will peak up a bit as its being maintained by the alternator. Where is the voltage on the band on the IP while running Chuck ? If it's middle band to just under 3/4 band thats normal. It will read under a half band with the key in the run position until you start. If that is what you see that is what I see on my 91 which is my DD Also the C4 is a battery Whore. Strange electrical things will occur if it's under volted. I've seen it before on my L98 90 and my 91 ZR-1. Also the car has voltage demands from the radio clock and the interior lights if the doors and/or hatch is open before it times out as off. Also voltage draw can occur if the visor lights are accidentally left on.
	Posted on: 2016/7/10 21:57
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bogus	Re: Low voltage indication...	#10
Grand Imperial Pooh-Bah San Pedro, CA 20859 Posts Member since: 2005/9/7 0:00	then it is time to resort to the last fix... Using a volt meter, have someone remove each fuse, one at a time, and see what happens to the voltage.
	Posted on: 2016/7/11 2:46
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GOLDCYLON	Re: Low voltage indication...	#11
Guru Newb Peoria, Arizona 23 Posts Member since: 2012/1/30 20:32	Another thought is the digital Automatic Transmission controller might be the volt vampire as well in order to maintain the transmission settings
	Posted on: 2016/7/11 13:28
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Schrade	Re: Low voltage indication...	#12
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Quote: bogus wrote: then it is time to resort to the last fix... Using a volt meter, have someone remove each fuse, one at a time, and see what happens to the voltage. Got it Andy; Daryll. I am hoping that IF it was not corrected when intermittent open was found in Tranny Shifter Indicator Light Harness, during CCM Field inspection, that it IS now. Won't re-check, until I/C is serviced by Bryan @ batee.com , since Cig Lighter Circuit might be down-current of I/C. Cig Lighter Circuit is Hot At All Times tho'... ? 2 emails sent there Daryll.................
	Posted on: 2016/7/11 14:07
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Schrade	Re: Low voltage indication...	#13
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Quote: Schrade wrote: I guess the question is, on what channel in ALDL is the B+ signal coming in on? This is an invalid question, since Tech 1 is not reading 11.2 V, from ALDL. ??? Only the ALDL Ground Channel is 'testable', for B+ Voltage, for Ground integrity. Tested GOOD. Tech 1 (and Tranny HandHeld Controller), are reading Cig Lighter Voltage, 11.2V, since each is powered THERE...
	Posted on: 2016/7/11 14:10
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BillH	Re: Low voltage indication...	#14
The Stig Moderator Reno 22702 Posts Member since: 2007/12/25 0:00	Quote: bogus wrote: then it is time to resort to the last fix... Using a volt meter, have someone remove each fuse, one at a time, and see what happens to the voltage. Yea, and along with that use the DMV on every fuse, are you getting above 12v. on any of them? BTW, I just checked the 92 for the hell of it. Batt - 12.4 Cig lighter - 12.3 Dash reading 11.9 (go figure. That's with a 2 month old Napa. Had a Diehard in there for 6 years that read 11.2 down to 10.7 at every cold startup and always started the car.
	Posted on: 2016/7/11 15:58
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BillH	Re: Low voltage indication...	#15
The Stig Moderator Reno 22702 Posts Member since: 2007/12/25 0:00	Quote: GOLDCYLON wrote: Also the C4 is a battery Whore. Strange electrical things will occur if it's under volted. I've seen it before on my L98 90 and my 91 ZR-1. Also the car has voltage demands from the radio clock and the interior lights if the doors and/or hatch is open before it times out as off. Yep, they will draw down even a new battery fairly fast, I here a C5 will too. I can only speak for a 92 but the hatch light is not in the timer circuit, it stays on until the hatch is shut. I made a small tool that depresses the hatch switch and holds it in the off position when I plan on having the hatch open for a while.
	Posted on: 2016/7/11 16:06
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Schrade	Re: Low voltage indication...	#16
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Negligible loss from Batt to cig lighter. Gotta' re-check cig Ground (think I already tested that GOOD), and Cig Supply, then trace circuit per FSM (IF still @ 11.2V)... Quote: BillH wrote: Yea, and along with that use the DMV on every fuse, are you getting above 12v. on any of them? BTW, I just checked the 92 for the hell of it. Batt - 12.4 Cig lighter - 12.3 Dash reading 11.9 (go figure. That's with a 2 month old Napa. Had a Diehard in there for 6 years that read 11.2 down to 10.7 at every cold startup and always started the car.
	Posted on: 2016/7/11 16:27
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Schrade	Re: Low voltage indication...	#17
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Just re-checked, motor Off, Ig On: Batt across terminals - 11.92 V (not right for new Batt). Tranny Controller Handheld (powered at Cig Lighter (Tech 1 will show same) ) - 11.4 V. so, compared to readings on 04/20, HIGHER V at Cig Lighter, with LOWER V at Batt - a positive. None-the-less, Batt @ 11.92 not right... And still too much V drop TO Cig Lighter.
	Posted on: 2016/7/11 16:47
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bogus	Re: Low voltage indication...	#18
Grand Imperial Pooh-Bah San Pedro, CA 20859 Posts Member since: 2005/9/7 0:00	11.9v at the battery is low. Put a charger on it... bring it up to 13 and then do the fuse box test. you need to find the draw...
	Posted on: 2016/7/11 17:57
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Schrade	Re: Low voltage indication...	#19
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Done; re-test post 24 hours... Alternator was rebuilt 2 years ago - must test Field Output as well... Quote: bogus wrote: 11.9v at the battery is low. Put a charger on it... bring it up to 13 and then do the fuse box test. you need to find the draw... Attach file: IMG_8638c.JPG (860.80 KB)
	Posted on: 2016/7/11 18:14
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GOLDCYLON	Re: Low voltage indication...	#20
Guru Newb Peoria, Arizona 23 Posts Member since: 2012/1/30 20:32	Quote: Schrade wrote: Quote: bogus wrote: then it is time to resort to the last fix... Using a volt meter, have someone remove each fuse, one at a time, and see what happens to the voltage. Got it Andy; Daryll. I am hoping that IF it was not corrected when intermittent open was found in Tranny Shifter Indicator Light Harness, during CCM Field inspection, that it IS now. Won't re-check, until I/C is serviced by Bryan @ batee.com , since Cig Lighter Circuit might be down-current of I/C. Cig Lighter Circuit is Hot At All Times tho'... ? 2 emails sent there Daryll................. Yes cig lighter is hot ALL the time. That is correct
	Posted on: 2016/7/11 20:28
	_________________ GOLDCYLON - 91 ZR-1 #2014 380 P&P&PCed,Ported Heads,Jeal headers,/Corsas/FIKSE FM-5s /LED TLs, HID Projectors,/R Baer Eradaspeed Rotors with Wilwood 6 piston front calipers
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Schrade	Re: Low voltage indication...	#21
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Update on Low V @ Cig Lighter (as indicated by Tech 1, and Tranny Module Controller Handheld, both of which are powered by C/L - and both of which show 11.7 V ATM). (I'm sure you can follow this, for feedback / thoughts) ------------------------------------------- The Battery in now, which I said was new, is NOT new (new one is in shed). The Batt in now WAS new when I bought the car in '12, although it had been discharged, repeatedly, by a cracked headlight gear. The headlight motor worm drive did not make proper contact, to OPEN the circuit. Motor did NOT run-on either, to help diagnosis by PO, of [his] new Battery drain. Batt Load Test @ Advance FAILED, in '12. It HAS however ALWAYS started the car, 4 years later! *So, even tho' Batt STILL starts car immediately, COULD IT BE THE SOURCE OF THE LOW V READING @ CIG LIGHTER???* I don't think so, but hope I'm wrong here. So I did this: The new Batt in shed, after Trickle charger overnight, went from 12.6 V, to 13.37 V. I plugged in the Handheld and got 11.7 V @ Cig Lighter (4 year old Batt now @ 12.24 V). Then, I put Jumper Cables from new Batt, to Batt in car now. New reading on Handheld is @ 11.9V - 0.2 V HIGHER. Good? Bad? Follow? Thoughts? I do NOT want to put in the new Batt, and blindly expect a solution here.................... Attach file: IMG_5054c.JPG (974.02 KB)
	Posted on: 2016/7/14 18:53 Edited by Schrade on 2016/7/14 19:24:26
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BillH	Re: Low voltage indication...	#22
The Stig Moderator Reno 22702 Posts Member since: 2007/12/25 0:00	Quote: Schrade wrote: The new Batt in shed, after Trickle charger overnight, went from 12.6 V, to 13.37 V. I plugged in the Handheld and got 11.7 V @ Cig Lighter (4 year old Batt now @ 12.24 V). Then, I put Jumper Cables from new Batt, to Batt in car now. New reading on Handheld is @ 11.9V - 0.2 V HIGHER. Good? Bad? You haven't mentioned checking other circuits (you may have done so thought). But I'd still put the voltmeter on the other circuits at the fuse box. If all of them read close to the cigar lighter, you may have a corroded ground somewhere. I had a bad battery in mine that would still start the car after sitting over night (11.1v on the dash) but sitting 2 or 3 nights and it wouldn't turn over. When I first got the 92, I read about ground problems on these cars, I pulled the cables/wires that I could get to and cleaned the connections. The main battery cable connection was rusty and a bit corroded. Wire wheeled it to bare metal and coated with Vaseline (which I've used on battery connections for years). Doesn't mean that I fixed anything, I just did it as maintenance.
	Posted on: 2016/7/15 14:22
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Schrade	Re: Low voltage indication...	#23
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	No, have not checked other circuits yet Bill; indeed have not looked @ FSM Wiring Schematic yet. Anytime I hack on the car, if I see a ground, or electrical connector, it comes apart, and gets cleaned / Di-Electric Greased... I have to have I/C serviced; will observe effects of service upon Cig Lite V afterwards. (and Matt, Andy - any chance you could edit the I/C service thread title? kant spel 2 gud - publik skool grad ) Quote: BillH wrote: You haven't mentioned checking other circuits (you may have done so thought). But I'd still put the voltmeter on the other circuits at the fuse box. If all of them read close to the cigar lighter, you may have a corroded ground somewhere. I had a bad battery in mine that would still start the car after sitting over night (11.1v on the dash) but sitting 2 or 3 nights and it wouldn't turn over. When I first got the 92, I read about ground problems on these cars, I pulled the cables/wires that I could get to and cleaned the connections. The main battery cable connection was rusty and a bit corroded. Wire wheeled it to bare metal and coated with Vaseline (which I've used on battery connections for years). Doesn't mean that I fixed anything, I just did it as maintenance.
	Posted on: 2016/7/15 18:01
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BillH	Re: Low voltage indication...	#24
The Stig Moderator Reno 22702 Posts Member since: 2007/12/25 0:00	Quote: Schrade wrote: (and Matt, Andy - any chance you could edit the I/C service thread title? kant spel 2 gud - publik skool grad Done...
	Posted on: 2016/7/15 20:00
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Schrade	Re: Low voltage indication...	#25
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Thanks there Bill; you're boards boss too DUH. Update when I/C is back from service here............ Quote: BillH wrote: Quote: Schrade wrote: (and Matt, Andy - any chance you could edit the I/C service thread title? kant spel 2 gud - publik skool grad Done...
	Posted on: 2016/7/15 21:13
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BillH	Re: Low voltage indication...	#26
The Stig Moderator Reno 22702 Posts Member since: 2007/12/25 0:00	Chuck, FYI for when you get to it. I took a couple minutes this morning and checked voltade on the fuses. Grounded the voltmeter to the engine. Volts across the battery - 12.41 Key off, 3 or 4 fuses were powered, all showed 12.36 Key on, EVERY fuse besides the above was lower. Some at 12.10 but most at 11.85. I really don't think the 11.9 at your cigar lighter should be of any concern.
	Posted on: 2016/7/16 21:55
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Schrade	Re: Low voltage indication...	#27
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Hmm... well - that's about as much 'knowing', as I've told buyer that I want to know (that it's not a problem), when coupled with fact that I read alternator output, when it IS running, @ Cig Lighter... ... and when coupled with fact that current Batt failed Load Test 4 years ago. Solved. Will update post new Batt, + serviced I/C install... Quote: BillH wrote: Chuck, FYI for when you get to it. I took a couple minutes this morning and checked voltade on the fuses. Grounded the voltmeter to the engine. Volts across the battery - 12.41 Key off, 3 or 4 fuses were powered, all showed 12.36 Key on, EVERY fuse besides the above was lower. Some at 12.10 but most at 11.85. I really don't think the 11.9 at your cigar lighter should be of any concern.
	Posted on: 2016/7/17 11:49
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Schrade	Re: Low voltage indication...	#28
Elite Guru eastern NC / e-i-e-i-o 1909 Posts Member since: 2008/8/15 2:01	Update; still 'Solved'... New Batt in (over a year old, never installed), I/C still out, Cig Lite V reading 11.9V on HandHeld for Tranny Cont Mod, spun up, 13.9V. (spun up instantly, smooth as a top - wanna' do the Nickle-On-Motor trick, but afraid if Nickle falls, I'll lose sleep (and NO start up [gas in] oil burn !!! ) ). Attach file: IMG_8682c.JPG (866.55 KB) IMG_8683c.JPG (789.68 KB)
	Posted on: 2016/7/22 20:37
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