| Please refresh us one more time about your problem.
Whether it is the control unit cutting the compressor off or the compressor itself is not working should be easily testable. There should be no possibility of an error to distinguish these possibilities. You do not need to take the a/c system apart to do this test. There is just one wire that brings in the voltage to run the compressor clutch. Turn the a/c on in the car and check the voltage on this wire, if you get battery voltage there and the compressor does not run, then it is the compressor clutch that is bad. Also if this is the case, you still dont have to replace the whole compressor, just the clutch can be replaced, and in some MB cars you dont even have to remove the compressor to do this. Alternatively, you can disconnect the connector on the compressor and apply battery voltage to the clucth coil terminal and determine if the compressor will engage and give you cold air. When doing this, make sure you apply the battery voltage to the clutch coil terminal and not the speed sensor terminal.
These two tests can tell you a lot about your a/c system.
If you dont get any voltage on the compressor terminal when you turn on the a/c, the first thing you have to look for is a controller module called the base module and the pressure switch on the drier.
The compressor connector is a 3 pin connector. Pins 1 and 2 are speed sensor terminals and Pin 3 is the compressor clutch terminal. The coil is grounded via the chasis. The color coes on the wire are:
Red/Blue is pin 1, White/Blue is pin 2 and Blue/Green is pin 3. The wire connected to pin 3 should most likely also be the thickest wire.
I would take the car to an auto air specialist (not the ones you have visited so far, I am not sure they are working in your best interest), ones that only do auto air and get a diagnosis. It could also be that you dont have sufficient refrigerant charge. Or take it to an auto parts store and see if anyone there could help you check the compressor, tell him that you know the pin configuration and just want to check if the compressor engages with external voltage.
Good-luck. |