A/C freaking out

[mostwired]

'96 318i - the A/C control unit stays blank, does not react to any buttons. Sometimes comes up by itself and works fine. Started to happen today - never before - just in time for the hot Florida summer... (sweaty smilie goes here - but it's not available)

Even when the unit is inoperative, the cold air blows out of the vents at speed.

After the car is turned off, the compressor makes bubbling sounds for a while, and if you look at the spindle inside the belt drive spindle, it rotates! (even though the belt and the spindle are stationary).

I checked fuses - all ok. Recently I measured the coolant pressure with a gauge - by opening the valve. Could it be something to do with that?

- Bad control unit? (why does compressor make all these weird sounds then?)
- Bad compressor? (but why does the control unit stay off?)

Any ideas, please?

 

[m5runner]

Sounds like you may have a faulty control unit, but at the same time, the compressor shouldn't be making that noise. Have you recharged it recently? I have to recharge my 92 325 at minimum, once a year for some reason. There are no leaks or anything so I don't know. I would get the AC system checked out first before worrying about the control unit.