Eureka!

Last week my climate control unit in my bimmer gave out. Initially I thought it was the computer shutting the thing down because the compressor failed or something, but the engine check showed a-ok. After googling my issue for a bit, I discovered that others were experiencing this problem around the 100k mile marker. It turns out that supposedly a capacitor failure in the climate control computer (located directly beneath the radio for those of you with an E36 series BMW) is at fault for this. His very detailed and accurate instructions let me fix what would have been a $600 replacement at the dealer for $.50 at the local electronics store (in my case Fry’s Electronics) and 2 hours of work.

I picked up the capacitor, removed the one detailed in the howto guide, and replaced it with the new one. Two notes I’d like to add: polarity does matter! So when replacing the capacitor, be sure to sodder the new one in with polarity directed the same way as the old one. You will need a volt-meter to test for polarity using the resistance (ohm) settings by switching the contacts of the voltmeter around when testing the capacitor. One way will result in a connection, the other way will not.

Also, another note: I succesfully used the capacitor that was mentioned in the how-to guide (.47uF50), however, the capacitor that I removed was a (u47F63). The guide mentions that there may be many capacitors that work, and I stuck to the one in the guide, since everyone has reported success with it. So far I have not had any problems.

Thanks, Richard Swope, for you most excellent guide!

[Edit: 8/5/2005 17:23 | Original Post: 7/5/2005 10:06]
I have been experiencing intermitent climate control failures after installing the new capacitor. However, my initial thoughts were that there was a cold sodder contact point, meaning that when I soddered the capacitor, it did not make sufficient contact with the contact on the board, and it cooled without gaining proper contact, leading to an intermittent or even failing electrical connection.

I had initially installed the capacitor by soddering it from the bottom, where one would expect the contacts to be. However, after taking it out and resoddering it, it appears the contacts are on the “upper” side of the board, so when you apply sodder, do it from the top, not the bottom.
After completing this “fix” it seems to be working fine so far. I’ll keep an eye on it and report on any further issues I may find.