2001 GTP A/C electrical problem

[fierogtpr]

Hi all, i had a little problem with my a/c. Short and simple story: 1. Fan didn't turn on when a/c on . 2. Cause damage to service port (high pressure valve)<--already replaced. 3. Damaged seal at compressor cluth. All because fan didn't turn on. relays and fuses all ok. Any idea? any wiring diagram? Thanks all.

[BNaylor]

What fan are you referring to? The engine cooling fans or the HVAC blower?

[fierogtpr]

Engine cooling fan.

[BNaylor]

The A/C hi/lo pressure switch in conjunction with the engine coolant temp sensor (ECT) does control cooling fan turn on when A/C is on. All controlled and monitored by the PCM module. For troubleshooting purposes disconnect the electrical connector to the ECT located under the thermostat and see if both fans come on in high speed mode. Do it with engine off and then start engine. Both fans should come on in about 5 seconds in fail safe mode. This may help split the baby and determine what direction to head.

[fierogtpr]

Thank you for the help my friend, very appreciated. I will try it

[fierogtpr]

Very good they turn on that way. Now What?? Bad A/C pressure switch?

[BNaylor]

How is the A/C system working or is the compressor turning on? Is it cooling properly? The refrigerant charge has to be within specs. The above test proves the ECT input is good and the PCM senses the inputs. Plus all outputs from the PCM module to the cooling fan relays and cooling fans are good so you can illiminate that part of the circuits.

[fierogtpr]

The a/c "was" working fine until one day the engine cooling fans didn't turn on, causing damage to service port or valve and compressor clutch seal. Service port (valve) replaced and refilled gas and found a small leak in compressor clutch but notice that the fan didn't turn on even with the required quantity of gas. Last thing for me to check is the a/c pressure sensor. Thanks for reply and help

[BNaylor]

I guess it could be. It is located by the accumulator. Hard to troubleshoot and unlike old cannot be jumped easily. The PCM provides a 5 volt reference signal to the pressure switch and depending on system pressure the sensor sends a varying signal within the proper threshold back to the PCM module.

When you turn on the A/C do you hear the A/C clutch engage? In most cases if the hi/lo switch was bad the compressor will not engage.

It may not help but try resetting the PCM module. Disconnect battery negative for a few hours.

Do you have the manual climate control or automatic-digital ACC?

[fierogtpr]

A/C pressure switch ok Reset is last thing to do. Thanks bro.