Hi all,

I did quite a bit of searching to try and figure this one out,but looking for additional information on troubleshooting.

I bought the car and it seems to have an aftermarket AC system in it, because in the fusebox under the hood there isn't an AC compressor (power) relay. I looked and there aren't even any terminals in the slot where the relay should go. I checked by pulling the ABS fuse out and there are terminals and wires terminated under it...but not for the ac compressor power...it seems it was relocated to the passenger side.



Both relays are on the shock tower on the passenger side of the vehicle



In the picture below, there is a quick disconnect for the single power wire that goes down to the compressor, which I think is grounded to the frame. I cannot get power at this point no matter what I've tried. I replaced those two relays with no joy.



I've reset the PCM relays and restarted the car and tried checking power there again and nothing. I get power into the relays, but nothing out of them.

Here is an additional picture and I'm not sure exactly what these components are, especially that two prong plug there with the loom pulled back.



Any recommendations on where to go from here? I had the car serviced at Midas, they recharged the system and made sure it would hold refridgerant, but I didn't let them troubleshoot the electrical problem cause they prolly would have taken too long and cost too high, so I'm looking into it myself.

 

Look on the build code tag, end of the driver's door, or in the glove box, for the RPO code "1LE". That was a "performance" option that included upgraded suspension, some minor differences, and was not available with A/C. That would explain the lack of the contacts for the A/C relays.

When what appears to be an aftermarket system was installed, did they add the pressure switch on the line near the recharge fitting? That interlocks the PCM to prevent it from turning on the A/C when the freon is low. I would think if someone added an aftermarket system, or even patched together the pieces of the stock system, they might have bypassed the PCM to eliminate the need for the pressure switch.

A/C control diagram, courtesy of Shoebox. Its for a 95, but your 94 would be similar.

http://shbox.com/1/hvac_compressor_control.jpg

 

Hi Injuneer,

I looked in the glovebox and it has a whole series of 3 digit lines and yes, near the end there is a 1LE there.

I just did a brief search and found that my car is supposedly one out of the 21 that were built in Canada. Is there a resource somewhere that explains the small differences in these Z28s?

Back to the AC problem, I'm not even sure where to look for the pressure switch. I know the accumulator/evaporator? is near the radiator on the passenger side near the battery box.

In the picture that shows the quick disconnect for the power wire to the compressor, could I at least check the compressor by running a hot wire to it from my +12vdc junction box/terminal block on the passenger wheel well?

I've heard of jumping the low pressure switch to bypass it if it was bad, but I don't even know where it is or what it looks like.

Thanks for the diagram to the system, but I'm not sure how much that might help considering what aftermarket components and wiring I have. I'm an avionics electrician, but this isn't no airplane or helicopter haha.