Chrysler PT Cruiser radiator cooling fan inop in A/C mode


#1

The car is a 2004 PT Cruiser. The fan comes on when the coolant temp gets hot, so I know it works. It does not come in air conditioner mode until the coolant is hot enough. If I put a good sized electric fan in front of the car, the A/C does blow cool for as long as the fan is there. If I remove the fan, the A/C high pressure limit switch cycles it off. Some person or persons unknown had unplugged a switch on the back side of the compressor. I assume that is the high pressure limit switch. I had to plug it back in to get a reading on my gauge. Due to an aluminum line running directly over the high pressure line port, I could not get a the high pressure hose to connect well. The R134a level appears to be OK.

I need to know what triggers the cooling fan to come on when the A/C is on. I need to know what limit switches, relays or modules are involved, and their locations.

Unfortunately I do not have a book or a wiring diagram for this car.


#2

The radiator fan should be on when the compressor clutch is engaged, the fan does not cycle on/off according to pressure like the larger Chryslers do.

That is a two speed radiator fan, the low speed may be burned out, high speed will be switched on when the coolant reaches a high temperature.

Check for power at the radiator fan, dark green is low speed, yellow is high speed.