I have recently done the 165 ecm swap on my 86 2.8 Firebird. While i was trying to get the AC working, there appears to be no power to the compressor. The system holds pressure just fine, so that is not an issue. Its the fact that the compressor will not kick on. This is irritating as I can not seem to find the problem. I did notice that there was a wire that was to be disconnected by the given pinouts. After my research, this was the AC clutch control. Now would this make the compressor circuit dead? If so, how to I get it working again? Its been over 90* lately with 60% humidity. I would like to get this AC working and charged up.

 

UPDATE:

When I jump the AC relay with the test light attached to ground the compressor will kick on and run until i remove the ground. After that, the compressor will not kick back on until I ground it again. There is 2 12oz cans of R134 in the system as of now. That should be enough to cycle the compressor.


Note: I tried jumping the plug on the low pressure switch with a paperclip, pin to pin and it did not kick on the compressor, but grounding one wire on the AC relay does turn it on. I'm lost.

 

What do you have in pin B8 on the 165?

Look here: http://www.eecis.udel.edu/~davis/z28...165v8tpi-6.jpg

Pin B8 controls the compressor clutch. Keep in mind that the switches only turn on and cut off the compressor based on the pressure in the system. The HVAC controls tell the ECM to turn the system on. The system is actually controlled by the ECM because of the electronics necessary to compensate for the additional load on the engine.

 

That is the AC signal wire, and it is in the right place. I think i have it fixed. Looking at other '165 schematics, I found some wires that needed connected and presto! Now I dont have to roast!

 

I'm having the same problem with my 1988 v6 Camaro, it's stock no ECM change, but the only way I can get my ac compressor to turn on is if I have hooked to a toggle switch, there is no power going through the wires that clip into the compressor. The fuse is good as well. Where else should I look for a problem at?

 

Click on the A/C controls links on this page:

http://92b4crs.tripod.com/86wiring/86wiringindex.html

They're actually in color (unlike most other manuals), so you will know what wire you need to look for. Keep in mind that the wires may be discolored for the last couple inches near the connector due to crud getting inside the loom, so you may need to peel back the loom to find out what color the wires really are.

Also, try swapping the A/C compressor clutch relay (by the brake booster, has a lot of green and blue wires in it) with one of the others next to it to see if maybe it's burned out.

:edit: Also, have the system pressure checked to make sure the base pressures are within reason for the pressure switches to engage. If the refrigerant pressure is too low, you'll never get the system working unless you recharge it.

 

Awesome, thanks for the link, I checked the relay and switches them over, and I think it out because when I switch them around my car won't start, but when I switch them back it starts right up

 

And do you know what the pressure is suppose to be for these