[s-cars] Seat Heater....weird stuff going on

[Kevin Day]

On Wed, Oct 26, 2005 at 12:41:30PM -0400, jpb3 wrote:
> Guys,
> Now that winter is approaching here in the mid-Atlantic I have turned the
> bun warmers on for the first time since last spring. When I bought the car 2
> years ago I would turn therm on to setting "3" and have a nice warm rear,
> anything below 3 and I wouldn't really feel it. Now two days ago when I used
> them again I turned to 3 and felt nothing. My first thought was "damn
> element broke!" but after cranking the dial up to 6 I felt it immediately
> and proceeded to have the notorious "swamp ass" dilemma within a minute. OK
> cool I thought, the element isn't broken at least. I turned the dial back to
> 5 and then 4 and noticed a cooling of the rump. Yesterday I started the dial
> out in position 4......nothing...switched to 5.......nothing....went to
> 6...ahh there is the heat again. This time when I backed it off to 4 it just
> cut off it seems, and when I switched back to 6...hello heat but no setting
> below that seems to work. Today 6 didn't work at all either so now I am left
> with a cold bum.
>  Am I correct in thinking that this may be the "dial" contraption that has
> finally given up or is this a symptom that the element was on it's way out?
> Anything else I should consider?


Sounds like an issue with the switch modules to me.  They regulate the
power to the element, and it could be that this regulator is bypassed on
"6" (i.e. full power).  I picked up a couple cheap on ebay after I broke
one trying to replace the bulb.  They are common to lots of different
Audis so shouldn't be too hard to find.  Might as well replace the bulbs
with LEDs while they're out (I think it was Fred M. who did an excellent
writeup on that procedure).

-Kevin