Air Conditioning questions (archive)

My 87 325i has a few problems. When I bought the car back in October I was told the A/C didn't work. I decided to do a little troubleshooting and have determined the following:

1) The compressor hub can be turned by hand
2) There is some pressure in the system
3) The high pressure switch is closed (as it should be)
4) The low pressure switch is open (indicates low freon)
5) Pressing the A/C switch inside causes:
a) The blue light behind the A/C switch comes on
b) The blower comes on low
c) The stage one fan comes on out side
d) The engine idle speeds up a touch

All this seems normal, except that even with the low pressure switch bypassed, the compressor clutch never engages.

I read about 2.5 ohms across the compressor clutch, so that seems good.

I never get 12V on the compressor lead. Ever.

Bentley's is oddly silent about the electricals behind the air conditioning system. The Haynes manual has more, although potentially incorrect information. For example, the Haynes manual doesn't even show the low pressure switch.

If that is the only ommission, it appears that the clutch should be running if the first stage fan comes on. They appear to get power from the same place.

Does anyone have any experience with this?

-- Joe

Follow Ups:

Re: Air Conditioning questions Manny 23:19 4/22/2001 (1)
- Re: Air Conditioning questions Joe Krzeszewski 00:44 4/23/2001 (0)

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