HVAC Blower motor resistor

[urpin]

Hi,

Has anyone replaced the HVAC blower motor resistor on the E34?
I believe mine is the non-sword type.
Just wondering if the problem is usually with the connections and can be repaired before I dig into it.

I get the usual failure mode where speeds 1-3 stop working and only speed 4 works.
After it cools down all the speeds will work again.

Thanks,

Bob

[shogun]

on the sword version it could be the plug connection sometimes. In case yours is the non sword type, just get another one, they are pretty cheap nowadays from the internet, aftermarket will do.
Sword can be repaired of course
I have some pics and some tips (http://www.bimmerboard.com/forums/posts/355700/)

[urpin]

Thanks for the input.
I know I can get another resistor for around 30 bucks.

Always looking for the cheapest way out.

-Bob

[genphreak]

on the sword version it could be the plug connection sometimes. In case yours is the non sword type, just get another one, they are pretty cheap nowadays from the internet, aftermarket will do.
Sword can be repaired of course
I have some pics and some tips (http://www.bimmerboard.com/forums/posts/355700/)I've repaired the plug type on e36 where the soldered joints just crack apart similarly to the sword and LKM issues. E34 plug may be similar to this. Its a bit trickier as there are rivets that go through plastic but its amazing what you can do. Usually these things go wrong if the pollen filter is not changed, reducing airflow. This causes the resisitor to live beyond its normal heat range, and plastic melts or soldered joints crack.

[urpin]

The resistor in the E36 is probably the same as in the E34.
What you described is what I was expecting to see since I do smell burning plastic sometimes when the fan stops working.
After fixing the solder joints, maybe a little high temp epoxy will help with the repair.
Thanks,

Bob

[BennyM]

I actually just walked in from replacing my resistor pack. The blower was starting to turn off intermittently just as you described. I bought a new one since repairing the old one didn't seem worth the time and effort. Anyway, when I pulled out the old pack, I found a bit of fuzz and a half-charred leaf stuck to the coils, which I believe explains the occasional faint burning smell that had been driving me crazy all spring and summer. I'd be curious to know how dirty others have found their resistor packs to be and if that contributes to the degradation of the circuit.

[Tiger]

They are all dirty somehow. Mine certainly was and same symptoms and smells like yours. New one did the trick. While the resistor is out, I cleaned teh area around tehre as much as I could with my fingers and whatever tools... and then took microfilter out to clean with vacuum.