I have a 1994 940 (non-turbo) sedan which has developed some climate control problems. The symptoms are that under load, the compressor clutch does not engage. When the compressor clutch is disconnected from the system, the engine operates as if it was engaged, i.e., the engine revs up a little to compensate for the drag of the compressor. I can also hear the switch in the climate control unit click when the a/c is turned on inside the cabin. The clutch was removed and inspected and is working properly. Refrigerant pressure does not appear to be a problem. All other components appear to be functioning properly. When the compressor is running, the air coming out of the vents is 38-40 degrees, so refrigerant is not an issue unless a leak developed yesterday. The a/c has been working intermittently since the problem first developed last week. The compressor will operate without warning for 5-10 minutes and then stop again without warning.

I previously received advice from this forum to check the soldering connections on the circuit board located in the climate control unit inside the cabin. A faulty connection was found and repaired and the a/c worked fine. I am now again having the same problems with the same symptoms. This time, no problems were found with the climate control unit. I have purchased a new (refurbished) climate control unit, however, it has not fixed the problem.

The symptoms have actually changed slightly now. The engine no longer revs if the clutch is disconnected and the cabin switch turned on. The climate control unit still clicks when turned on, however.

Any ideas? I'm thinking possibly a loose connection somewhere. Any chance it is the LHJetronic/Regina control module behind the right kick panel?