Got the car running today, no cooling issues, but now I don't have any AC. This is on a 95.

Its been sitting for the last three years so I may have to recharge it.

But, the electronic HVAC panel also seems to be acting weird. I can get it to adjust temperatures, but the fan button with the up and down arrows don't seem to do anything.

I've replaced that unit under the hood at the blower with the two plugs. So, I can put the temperature down to 60 but no cool air. I think I have 134a which of course hasn't been used in 3 years. That fan button on the top doesn't do anything and the auto button on the bottom left just has the fan going full speed.

Start with a couple cans of 134a?

yes. Add some refrigerant and go from there. It more than likely leached out. Don't forget the oil!!!

I'd ckeck the pressure on the low side to see if you have any pressure at all. If you have some pressure, you have a slow leak. If you have no pressure could be one of many possible problems. First you have to see if it holds freon. You may have to jumper the compressor to get it to turn while adding refrigerent and get it into the green zone on the pressure guage.

Before you add any cans you need to check the high/low side pressures. A/C systems are closed and shouldn't lose freon. Adding more can damage the system.

Figure out the head unit issue first, pull codes, then check the freon and other components. If you need to add freon, you have a leak somewhere.

Matthew

If you get R134A get it with dye so you can detect the leak. Matt is right that the system should not leak but sometimes a defective schrader valve will release small undetectable quantities over time. You did have it sitting for quite awhile. O rings, compressors, lines and other components can fail. You can always get it tested for around $40 at a local shop.

Thank you all. I did take look around and saw some oily dirt around one of the joints, so I'm sure there is an issue there. I bought a seal kit consisting of all the o-rings, so I'll start those replacements. Then I'll have it vacuumed and refill it.

1. Now, here's a question. There is a unit up by the firewall...also where the coolant lines go in. Is that the evaporator? Now, there is a T fitting up there and out of that T fitting is a plug, goes into the electrical harness. Before it reaches the harness, the wires that lead to that plug are exposed as the plastic coating on the wires is completely melted, disintegrated off. I guess I need to repair those wires or get a new plug...the small brown keeper on the plug that locks it to the fitting also broke off. What does that plug do?

2. Further, where the lines go into that box, there's some gooey black substance right on where they enter. Is it really gooey black or is that a melted piece of rubber I need to replace?

I think the electronic unit inside is working. I pumped the temperature all the way up and the fans slowed way down. (Its 93 here today.)

3. Finally, I had an issue with the digital display in the center of the instrument panel. I replaced the entire speedometer cluster with the display from another car. Now the dispay is not faded anymore. That's first. BUT now the fuel gauge is registering empty (this was when i first got the car started). Yesterday while driving it the fuel gauge registered full, but the range said 102. I filled it up with 11 gallons. So it stayed full which is expected.

Today I replaced the negative terminal as it was cross threaded. When I reconnected the fuel gauge reads empty, range 0 and I have no bars. Do I also have an issue with the fuel sender?

how do you jump the compressor to turn it on?

Quote:

I would be shocked if you average can of r134 would over power the near equal pressure of a full system.

R134 is more prone to storage based leakage because it is molecularly smaller than R12.

Ok, the fuel indicator is back on full after having shown empty for the drive. I found some old threads on how to take it out and maybe fix it.

Per the FSM, the sensor I found where the wires were bare is the AC pressure sensor. I guess I can lead new wires or wrap the wires in place, but the copper is looking very dingy, not bright.

My plan is to:

1. Have the system evacuated
2. Then I'll change o-rings,
3. Have vacuum drawn and see if it leaks
4. Put in new 134a.

Does that sound right? Steps 2 and 4 I'll do myself.

Ralf

The black gooey stuff is sealant, don't worry about it.

You can remove the head unit and clean the buttons with contact cleaner, a pencil eraser, fine emery cloth, etc. It's common that they get gummed up.

Sounds like your procedure is pretty good. Since you are opening the system, replace the accumulator and orifice tube, too.

Quote:

Jumper wire in the a/c pressure switch.

I'm a commercial A/C mechanic (not automotive) but ALL open
drive compressors leak a little, especially when not used.
The seal gets dry & it seeps out. Your plan is good, but leak
test it with pressure, not in a vacuum, its better that way.

Good info, Benny!

Appreciate the information. I will have to get on that once I can find a shop I trust around here.

As for the frayed wires on the pressure switch, it worries me. I thought I touched them at one point the other night and heard the clutch engage on the compressor. Then could not recreate that. I'll be looking for a fuse, but I'm thinking either repair the insulation or find a junkyard piece and splice it in. One way or another, I have to get that switch electrical fixed!!

Check to see if you are getting power to the pressure switch, easy to do and might help point you in the right direction.

OK, wait a minute, I've read about jumpering the switch and read Matthews reply above.

I may be overthinking this so bear with me. I unplug the two wires that go to the switch, then I jumper the switch OR I jumper the plug that goes to the switch...(just occurred to me while writing this)...because the switch wouldn't have power without the electrical connection but jumpering the plug would do it as it has power and would read the jumper wire! Did I get that right????

Ralf

Jump the two wires together (the plug), not the switch.

Quote:

Exactly. Use a jumper wire or a paperclip and stick them in the female sockets. Just don't hold it too long if you are low on freon because it could cause damage.

I did the jumper process, got electrical tape around the exposed wiring (why did the wire insulation peel off??) and the compressor turned on. Left it enough to see the clutch worked, then tried to make a decision as to whether to fix myself or take away.

I then went on a cruise to think about it , got back on
Saturday and took the car in on Tuesday to be repaired. About $120 all told, but I think next AC work I'll try myself. The information here is just too good and detailed not to try it myself!!!

I was wondering why the wire wore out, too. In about 1990, SAE changed the composition of wire insulation and that should have stopped it.

I know my 92 harness, tho a bit dingy, is still in excellent condition.

Yes, both the plastic off the wire flaked off. Right up to where it went into the harness. I covered it and went to the junkyard to see if I could find a compatible plug, but could not find anything, even off other 95 cars. The plugs were different, smaller and the wires were different colors.

Rock Auto has a pot load of electrical connectors for GM products. I am sure you will be able to find a lead there.

You're not kidding, they do have a lot. I just need to find the right one!

Quote:

If the one you have works just 'paint' the wires with some liquid electrical tape.

Wow, I hadn't thought about that alternative. Yes, the bare wires did not break, it all works once I plugged it back in!