MrLonely

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So I've been working on this car for quite some time. I'm going to give some background on the heat and a/c so you have a better understanding of the issue. So before I go the car running I had an old battery in the car and all it could power were the courtesy lights, headlights and, even the blower for the heat/ac. Little later on I got the car running with a new battery installed and was actually able to turn the a/c on (and surprisingly lowing cold after 10 long years). After that the car sat for quite some time because my transmission needed a rebuild.

After finishing the rebuild and installing the tranny in the car, both the blower and heat/ac stopped working. I didn't really think of of it at first because I had yet to take apart the dash and check wiring and such. However, I have now done that and as far as I can see, the only electrical things that don't work are my horn and the heat/ac. So I took out my a/c control unit and took it apart just giving it a once over. I checked all the switches and such to make sure they operated correctly and they seem to work fine. I checked that the brown accessory power lead is giving power from the fuse block, and it is. So I've narrowed it down the heat/ac wiring harness. There are two relays, a blower motor resistor, and I believe an ambient control switch(I think, its a two pin connector). I took out the relays and tested them with an external battery. Both would click when energized so I am assuming that they are fine. That leaves the resistor and the ambient control switch which I'm assuming are fine but I could be wrong. I don't really know how to test those. I did a continuity test on the resistor and it seems to all be connected but im not sure what that means, I'd like it if that were the problem because its an easy fix.

I am not sure what else could be the problem unless I'm missing something. There is a power lead I believe off of the generator/alternator but I don't have a wiring diagram to see how it ties into the heater/ac wiring harness. Also know that my a/c compressor does not kick on at all.

Anyway I hope this information can spark an idea as to what could be the problem.

Thanks!

Andrew
 

melsg5

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This link has a Firebird wiring diagram which is similar or perhaps the same.
 

MrLonely

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Assuming the brown accessory power wire you referenced in your post is feeding into the heater master switch, is there power coming out of that switch?
Using my external battery, I did check to make sure the voltage come out of the switch, so I know that the a/c control switch is working fine. I wanted to make sure that it really wasn't the control unit that was the issue.
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MrLonely

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This link has a Firebird wiring diagram which is similar or perhaps the same.
I appreciate it, I will check it out and see how it matches up.
 
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