My 1999 M3 convertible's climate control has started acting up. The
display of temperatures set and fan speed will dim, then go out and it
will turn off the fan. It seems to also turn on the rear window
defogging fan. If I thump the dash next to it, that will sometimes
get it to work again (the "bigger hammer" repair theory).
I've seen threads and web articles on replacing a capacitor inside the
controller and I've got the tech skills to do that. Is that likely to
solve the problem? The symptoms I've got don't seem to quite mesh
with the ones shown for that solution.
Actually - the replace the capacitor works because the job entails
resoldering the new capacitor in. The problem isn't the capacitor - it's
a cracked solder joint (which thumping the dash closes up..) Since you
have the skills - reflowing the solder joints on the circuit board is a
cheap/free thing to try first.
Well considering that I've been out in Redlands a few times the past
couple weeks where it's around 100* during the day, I'm *thrilled*
that the A/C works again. If it dies again, well, I'll try to re-redo
it. But I'm gonna hope I don't have to, regardless. :)
The same thing works on early 90's-vintage Honda main relays, which are
also prone to failure. I've reflowed the solder joints on two of them
(adding some fresh solder to all the joints each time). Neither ever
failed again, and one of the cars is still in service 50K+ miles later.
Of course it worked... who you gonna believe? Some company or what some
unknown person tells you on the Internet?
Oh - right.
You can buy me a beer sometime.. :)
(This also works on Motronic 1.1 boxes used on the E28/E24 series.. on
those the output transistor leads break free - a bit of resoldering and
they're good to go. Bet ModuleMaster gets $200-300 for that little trick.)
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