A/C and Cruise doesn't work
 

'94 Z28. Did a minor search but didn't find anything. Just bought this car and the compressor won't kick in no matter where I try to jump it. Normally I would chalk it up to the compressor being bad but I noticed that the A/C and the Cruise Control are on the same fuse(fuse is good). Cruise doesn't work either, so I was wondering if this was a common problem or not, or even if someone has run across this before. The guy I got it from said he had someone look at it and they said it was in the computer?? Ideas??

I'm having the exact same problem...

If you have any A/C codes stored in the computer the compressor wont turn on.

Even if you try to jump it/ hot wire it?

You don't want to hot wire it you could fry the compruter. Get A code reader and check the codes clear them after you find out whats wrong.

Problem is, it's a '94. OBD1 system.

A/C code doesn't explain why the A/C and Cruise stopped working at the same time with good fuses...

have you figured out your problem yet? my crusie control stopped working but my a/c is still working fine

Nope, too hot to work on it and fix the A/C. lol I've tried all I can think of right now. And I don't know if they went out at the same time. I just know they both weren't working when I got the car.

checked fuses and relays?

My cruise has never worked on my car and the A/C didn't work when I bought my car. Probably 2 separate problems.

If you get that cruise figured out, let me know. I never really tried to fix it since I've always had other problems which seemed more important.

Yea, fuses are good and so are the relays as far as I can tell. I also jumped the terminals for the a/c relay and still nothing happened. So I want to say it's 2 seperate problems but I don't know? Lol

Do you have pressure in the A/C system? If you don't have a guage just take a key or screwdriver and try one of the ports just like you would let air out of a tire. You should get air (freon actually) mixed with a green liquid. But you're saying you jumped it off and the compressor still isn't cutting on so this is probably not going to help you diagnose the problem. At least you'll know if all leaked out or if it's still holding.

I believe you can tune out the A/C in the pcm, but not sure why anyone would do that. I know you can set the compressor to cut off at a certain % of TPS. It's set on like 94% stock. I lowered mine to 50%, but I guess if you lowered it to 0% it would never cut on, even if you did jump the switch.

See if you can turn the compressor by hand with the belt off (not the pulley, but the clutch part). It should be a little hard to turn, but it will turn if it's not locked up.

Also, you can get a multimeter on the 2 wires going to the compressor and check for voltage. I believe you should get a full 12 volts with the A/C on. That will tell you if the computer is commanding the A/C comp to come on. If so, then then problem is inside the compressor.

I can turn the clutch itself so it's not locked up. And I've jumped those 2 wires at the compressor to try to get it started and nothing.

Check the relay as well but unplug the battery for a few minutes and then try it. Thats what I do

If it was locked up your belt would just spin over it and the car would be pouring smoke...Ask how I know :D

have you unplugged the compressor and tested for voltage? Adding power without verify Voltage is how things fry out. I would make sure ALL the fuses are good first, in the dash panel the hvac control fuse could be bad, start checking to see where power is/not and go from there.

As for the Cruise, its under the driver side front bumper, might want to test for power there as well, might have a blown out fusable link now power is nt being supplied. thats just a guess though without me doing the diag

Haven't bothered with it in a while but yesterday I pulled the plug on the compressor and put a test light on it with the ignition switch on and the dash switch on A/C. No power. Anything?

replace the fuse, i believe the a/c and cruise works off the same fuse

Fuse is good. Freon is empty now. I pushed in the schrader valve for about 5 seconds and nothing came out anymore. lol