1992 940 AC Clutch Engagement

[rrussell]

Hello,

I have a 92 940 and I believe I have an electrical issue with the ac clutch being engaged. Basically blown fuse on fuse #16 started my issue. After replacement of fuse the ac clutch would not engage. I was not recieving power at the low air switch, metering on pin #10 of the climate control unit with ac on was no power. If I put power in either spots (low air or pin #10 on back of climate harness) the compressor engages and works perfectly.

I had thought the internal relay of the climate control unit was bad, tried soldering connections with no luck. Ran down to the junk yard and got another climate control unit. With the new unit the compressor is now cycling but after it runs a bit its like the clutch is slipping (i.e. its not recieving enough power to hold it in???), if I run power directly from the battery it doesnt behave this way.

A thing to note, the radiator (electric) fan is not coming on at the same time the compressor clutch engages. The radiator fan seems to only come on when the temp sensor tells it. I found a relay down by the battery on the passenger side that has 3 connections coming to it. I am wondering if this relay could be my problem? I am running out of ideas on what to check. Any one help?

I am looking at wiring diagram located here for the Regina system: http://www.v8volvo.se/mekartips/volvo/F ... ichell.pdf

[jimmy57]

I think a 92 has the capacitor in the clutch coil wire on side of compressor. If it has it you will know it by seeing a square light green side on a black square piece on a lug on one of the compressor mounting "ears".
The capacitors can go open or short.
The cap is there to protect fuel inj control unit from the 50V or higher spike on compressor off.
I know of no source for the cap.