Ac switch and other issues

[steelynorm]

Okay so I picked up my new to me e30 a couple of weeks ago and have been trying to diagnose ac issue.
So aux fan and ac are not engaging.

However this morning with the ignition in the run position
The fan blower dial to zero
When I depress blue ac button the switch lights up a dull blue and the fan blower comes on at low speed
That is not right is it?

[tomstin]

You need to track down a wiring diagram for your year but... The vent slider needs to be about half way, there are images out there. Next, there is a sensor in the evaporator under the dash (drivers side)(evaporator temp sensor) to shut off the AC if it freezes over, that can go bad (stuck open). Then you have the low pressure switch on the dryer. All those have to be good to get power to the compressor.

As for the fan, check the fuses and the resistor on the front of the fan. Ceramic block about a half inch square and an inch and a half long (as I recall).

[steelynorm]

Re:

Thanks for those spots to check out.
I have done the jumped wire technique at temp gauge on radiator,
Fan kicks on for both wires
I have checked fuses for power
I think I am having relay issues on relay k1
Ok thanks, I was hoping for an easy fix

[jeffnhiscars]

If your aux fan comes on when you jump the wires then the resistor is bad. It's ok to jump it permanently so it runs on high 24/7 just update the low speed fuse to match the high speed fuse

If the compressor isn't engaging check the vent slider as was suggested and check for 12v at the clutch. After that you should throw gauges on it to check the charge before you replace anything.