EG4: Air Con half works

[shebangs]

In the EG I just bought, The Air Con doesn't work on 1 or 2. 3 and 4 it works without a problem.

Anyone seen this before? Just checking if it could be a quick fix before I take it to auto electrician? I have a feeling it's linked to the aftermarket HU on it.

[dAzLr]

it'll be something to do with the cord on the back of the switch that sets the speed settings of the fan

[omgzilla]

Not sure if it's the same as any other cars i've worked on but usually in built with the fan speed adjustment unit is an A/C compressor engage/disengage switch. If you have the A/C switched to ON but your fan speed is set to zero - the A/C compressor remains disengaged. Once you increase the fan speed from zero to 1, 2, 3 or 4 (while the A/C is still switched on) the A/C compressor is engaged.

Possibly a fault in the switch not engaging the a/c compressor on the lower fan speed stages?

Do the different fan speeds function correctly?

[Moya]

Do the different fan speeds function correctly?
Yep! Annoying because after the 2 minutes it takes to cool the car down, it gets cold :)

How much would an auto electrician charge to fix this?

[omgzilla]

I would estimate at most of 2 hours at ~$100/hr labour plus parts.

If you know someone with the same car that wouldn't mind you borrowing their a/c control block to test it out would be ideal.

I'd be thinking towards something in the a/c switching in your fan speed switch set.

[EG30]

it's the fan speed resistor that has gone faulty.

[omgzilla]

it's the fan speed resistor that has gone faulty.

I thought this to begin with, then dismissed it as it affects the fan speed not A/C directly.

Then again the fan speed also switches A/C compressor as I explained before - so what EG30 is saying sounds very plausible.

I know that BMW fan speed resistors are a common issue (on E46's anyway).