Anyone here know how these function? I've seen ebay sales of switches with a numbered wheel - do they stay off at "0" and then change resistance, or have a feedback line from a temp sensor? Just trying to find some info and getting nowhere with other online forums. Thanks!

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

The zero position is off and there is a switch-like detent when you rotate the wheel to the on position (numbers 1 through 5). I believe the wheels are just potentiometers that send a signal to the seat heat controller. There maybe a feedback but on my Jetta if you leave it on max it seems to just get hotter and hotter with no impression that they are switching on and off to maintain temperature.

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1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown

My FSM for '94 S4 (92+ 100/S4/A6/S6) shows a seat temperature sensor (continuity checking routine) and indicates the sensor and heated seat element are one unit. Haven't checked the wiring diagram but I assume a connection exists from the switch (control wheel) to the heating element.

Plug connector (at seat) indicates 6 connectors: 1&5 = Seat heat element; 2&4 = temp sensor; 3&6 = seatback heat elements.

Let me know if you need different info and I will try to confirm.

Volkswagen was giving free seats for tdi jettas. The elements got so hot they would burn through the seat cover and damage your clothes. Never happened on ours but we did not use the number five setting.

Likewise on my VW TDI NB. Man those suckers do work! For me, #2 setting is about Max.

hey, thanks guys, this is more good info for me. I'm inclined to get a pair of VW or Audi switches and see how it goes. I'd like the BMW fedback feature, but it's really not necessary. I might just try one of the thermal break Saab switches too. Knowing that the wheel switches have a shutoff is key.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.