AC dead. Compressor clutch not engaging. Also, interior lights....

[stjobs]

All of a sudden my AC stopped blowing cold air. The compressor sounds like it's engaging, with a faint whine, but the rpms don't drop like usual and looking at the car the center of the clutch isn't moving. I spun the clutch center by hand with the engine off, and it spins smoothly. There's a little intermittent resistance from the magnets, but the bearings for the clutch seem to be fine.

There's not a refrigerant leak. No wetness under the car, no oily discharge around the hoses. Also, this malfunction happened within a week period. I drove the car one weekend, the AC was ice cold. Next weekend, nothing.

I should check the voltage being supplied to the clutch as the next step, correct? What should this reading be with the compressor switch in the cabin engaged?

Also, none of my interior lights work. All the fuses are fine, and this happened all of a sudden also (a few days before the AC failure). The headlights come on, but the accompanying interior lights don't. I want to check the dimmer before I have to tear apart the interior looking for a short or broken connection. I assume since all of them went off together that the interior lights are wired in series?

If that's the case, what is the typical procedure for locating a short or failed connection?

Also, how do I get the dimmer switch out of the dash? This is on a 1997 Z3.

Thanks,
stjobs

[Ferris]

There should be a relay to the compressor clutch check that first.

[stjobs]

Ferris, any clue which relay?

I checked the voltage for the wire going to the compressor clutch and it wasn't receiving any.

[Ferris]

I really don't know . I'll see what I can dig up. The setup is either climate control->DME->Relay or DME->relay<-climate control. I'm not sure if it's interlocking senerio or the DME handles it all. if you get a copy of ETM it'll help alot, I'm still trying to find one.