89 535i Heater Fan Problems...

[LeaTHER OpT. 28]

I have an 89 535i and the heater is a little goofy. It works ALL the time when it is switched to high, but when it is on 1, 2, or 3, it rarely works, but sometimes it does. Its really weird and can be a little aggravating. Also, the A/C does not work AT ALL. Does anyone have any suggestions??

[pada]

Hi ... when you say your heater doesn't work, I'm assuming you're referring to your blower; no air flow, right?

A very common failure on your model was the Blower Motor Resistor Pack. Usually, when it goes it's gone, but I'd still say that's the cause of your problem.

The Resitor Pack allows full-on power to the Blower Motor when the switch is in high postion and each increment down, i.e., positions 3, 2, 1, it adds more electrical resistance to the line from the power source to the blower motor, thus lowering it's speed more each time. And when the Resitor Pack goes bad, it creates no resistance, allowing only full battery power, thus only high fan speed.

Bottom line, replace the Blower Motor Resistor and you'll be good to go.

The A/C is another matter ... you can check the fuse for the A/C Compressor, check that the Compressor belt is tight, basic stuff like that ... otherwise you'll probably have to take it to a reputable repair shop for pressure/leakdown testing.


Good luck,

Paul (pada)
89 325iA
204k and still looks new!