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Old 07-30-2004, 12:27 AM
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sixto sixto is offline
smoke gets in your eyes
 
Join Date: Jun 2000
Location: Eastern TN
Posts: 20,841
Things more or less related to AC compressor nonfunction:

- oil or dirt geting into the AC compressor clutch -- if it causes the clutch to slip, the ACC controller or Klima relay (if equipped) will think the compressor is binding and cut power to the clutch

- faulty engine rpm signal into ACC controller or Klima relay (if equipped)

- faulty cabin temp sensor

- faulty engine temp sensor

- low refrigerant pressure

- faulty solder joints in ACC PBU

- faulty solder joints in Klima relay (if equipped)

If your car has a Klima relay, you have an intermediate point at which to probe whether the problem is upstream or downstream of the Klima relay. BTW, the Klima relay considers compressor rpm and engine temp to determine whether to pass the ACC PBU AC compressor on signal to the compressor. Hook up a test light to the AC compressor on pin at the Klima relay to localize the fault. Then take it from there.

If there's no Klima relay, I don't know where to begin besides reflowing the ACC PBU solder joints. Which BTW is a PITA to take apart.

Sixto
95 S420
87 300SDL

Last edited by sixto; 07-30-2004 at 12:58 AM.
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