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Biglex 06-22-2007 05:48 AM

ac compressor
Anyone know how to test to see if the a/c compressor is ok? I read on here a while back you could bridge some connection to force it to kick on, but I cant find it anywhere. Talkin about on my 92 300D.


Biglex 06-22-2007 07:26 PM


Matt L 06-22-2007 09:40 PM

I think you have a switch on the high-side line which opens if the pressure is too low. If so, and it is open, you can bridge that switch. Don't do it for very long without adding refrigerant.

Bill Ladd 06-23-2007 12:54 AM

Don't know about a '92 300D, but on mine there is a accumulator/dryer above the compressor mounted in the engine bay. Up front very close to the radiator. There is a low pressure switch on it to prevent the compressor from burning up if the charge is low.

If you can find yours -- while your car is running, pull the two wires off of it and touch them together. If your compressor clutch kicks in and the compressor runs, you might be okay. If the compressor is locked up, the belt will start slipping and squealing.

This might not be good at all if you have a toothed serpentine belt.

Anyway, that's how I determined the compressor was dead on my car.

Oh -- there's another switch on the accumulator which switches on the auxiliary fan. If you have one and touch those leads together, you'll know it when your fan kicks on.

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