Unique A/C problem

[15Michaeljoseph]

Believe me guys, I tried to find something similar to my issue on the web and on this forum, but there isn't one. It's starting to get hot in MA and I want to get my A/C working.

Car's a 1987 325is and is equipped with the bosch-behr green label compressor, type 3 i think they call it.

My mother is the PO and said she had the r134a conversion done, and that it did blow cold up untill a few years ago.

when the car is running and you hit the snowflake A/C button, it lights up, however the compressor doesn't engage, and the aux fan doesn't kick on. and I have tried adding refrigerant to make it kick on, but still nothing. So what I was thinking is that the compressor clutch is bad, but I recently read something that said that if the low or high (cant remember which) fan relay is bad, then the compressor also won't turn on. so is it a coincidence that both the fan and the compressor don't work, or could they be related? I've checked the wiring out and nothing's broken. I've taken off connectors and hit them with contact cleaner.
any help is much appreciated.


--Mike

[Eddie Haskell]

To check the a/c clutch you can jump the clutch with 12v. Just touch the one wire connector and listen for the solenoid.

[15Michaeljoseph]

To check the a/c clutch you can jump the clutch with 12v. Just touch the one wire connector and listen for the solenoid.

what would you say is safe to jump the compressor? I was thinking about using the 12v positive pin on the winshield washer pump...is that okay?


--Mike

[jlevie]

The fan switch and the compressor aren't interlocked. What you are seeing could be a problem with AC/Fan control signal making it from the HVAC panel to the fan control low speed relay and to the compressor control. Or you could have two separate problems. One with the fan and one with the compressor. Use the wiring diagrams from http://wedophones.com/BMWManualsLead.htm to trace from the HVAC panel through the circuits.

[jeffnhiscars]

Another possiblility that might explain both issues is that there is a microswitch in the middle slider on your HVAC controls. It has to be 2/3-3/4 to the right to activate the AC. The snowflake will still light even if the slider is in the off (left side) position

[15Michaeljoseph]

Another possiblility that might explain both issues is that there is a microswitch in the middle slider on your HVAC controls. It has to be 2/3-3/4 to the right to activate the AC. The snowflake will still light even if the slider is in the off (left side) position

do these switches break? :???:

[jeffnhiscars]

do these switches break? :???:

Any switch can stop working. In this case one of the contacts is on a plastic tab than can in fact break. It may just be dirty or worn.

[mrgraphics]

Also remember, there are sensors on the dryer that determines if there is enough pressure to run the compressor. If these sensors are bad, or the wiring is loose, the compressor won't turn on even if the snowflake light is on.

That was my problem - jiggled the wires on the dryer and everything kicked on.

[15Michaeljoseph]

Any switch can stop working. In this case one of the contacts is on a plastic tab than can in fact break. It may just be dirty or worn.

i'll be taking a peek at this


--Mike