Please help/advise, 240SX AC disaster

[kendem]

Please help/advise,I have a 1991 240sx. My car’s AC would work intermittently and I discovered that the problem was induced by cabin heat. Once the cabin was cool, reguardless of how hot the outside temperature is the AC worked fine.

So after researching and hearing other solutions I replaced the thermister (bought from the dealer for about $32) about 4 months ago. That’s the sensor that mounts to the outside of the cooling unit and has a temperature probe sensor that goes into the cooling unit case and mounts to the exhaust side of the evaporator coil. It has a connector with 3 thin wires that connects to the thermister, the center wire is green/black, one is blue and the other blue/red.

Well that fixed the problem for a while. Then the problem returned again during this latest heat wave here in So. Cal. Extreme cabin heat caused the compressor to cycle off and on repeating the same symptoms as before. Again however, once the cabin is cool, the compressor stays on.

So I had the brilliant idea to bypass the thermister sensor. I left the car in the hot sun with the windows rolled up to produce the problem. Then, not knowing what I was doing, I removed the wire harness from the thermister and tried to jump the connector wires to see if I could get the compressor to stay on. I jumped the blue to the blue/red wire and tried different combinations. Sucide!!! By jumping those wires I think I fried something under my dash board because it smelled like it, and now the AC doesn’t work at all.

I even tried to test the compressor by connecting a 12volt tester from the + battery terminal directly to the blue wire that goes to the compressor and the compressor clutch didn’t ‘click’ while the car was running with the ac on.

So does anybody know what those 3 little wires are that connect to the thermister? And did I completely destroy my entire AC wiring system by jumping those wires? I fear this is going to be extremely costly to fix.

In conclusion, I really feel stupid for jumping those wires when not knowing exactly what they connect to. I just figured the green/black wire was the ground and one of the blue wires was the live going into the thermister and the other blue was the signal going to the compressor. Please help,Ken