Nothing is heating up in the front seats.

[AndrewGuidon67]

......and they still haven't done it since I purchased the vehicle. As someone who dislikes them, I've never given them much thought. After all, the only time you'll notice the leather seats are when you first sit in them, and even then, they're still cold. Nonetheless, she like them (and uses them frequently in her W169)...and as they are currently the sole malfunctioning component in the vehicle, I figured it was time to check them out. Both fuses 44 and 45, which are 30 amp fuses located on the boot fuse board, should work; there appears to be some misunderstanding regarding the function of the relay. The fuse number 82 does not appear on my fuse board, however it does in my guidebook.Also, I don't have any of the fuses listed online (62 and/or 64), and I don't even have a holder for those fuses in my vehicle. I verified the relay, which is supposedly the F-connector on the back panel. Everything seems to be in order.It should be noted that the fuse position map was not included with the vehicle when I purchased it; however, I was able to download one for the correct model and year.
If I turn on all three lights on the switch, my seat remains cold, and after ten or fifteen seconds, the lights go off. Even if it remains cold, the passenger side switch remains turned on.On rare occasions, I may have detected a slight heat of the front edge of the passenger seat. Both seats have their own heating elements, one for the base and one for the backrest....To think that all four components have vanished leaves me feeling bewildered. Thanks to the discrepancy in the data, I'm still not sure I'm checking the correct fuses and relays. As again, I would greatly appreciate any information that you can provide.


WD212 E350CDI from 2010.

[LiamTheGreat]

Are the power supply and grounding at the plugs under the chairs something you have been able to check?

[AndrewGuidon67]

My next move is to double-check that I'm examining the correct fuses and relays.

[tonysoprano]

As is the situation with my SL's driver's seat base cushion—the backrest heats up, but the base doesn't; there's electricity in the socket it plugs into, but no heat—the most common issue with heated seats appears to be wires breaking within the heating pads. Eventually, I'll switch out the passenger side working cushion for the working one. If that fixes it, I'll take off the leather cover and look for the problem in the heat pad (I'm hoping to find a faulty wire somewhere).

[AndrewGuidon67]

Mysteriously, all four of them would be unsuccessful.it on my vehicle. Maybe just one or two, but all four? We need to conduct additional research.

[samjonescars]

I see that it sounds implausible, but in the case you mentioned, one seat's switch lights go off after a few seconds while the other's stay on as expected, maybe with some heat on that portion of the seat...

The odds are high that it's the result of multiple mistakes.

[Dino_Cars]

I think it's a good place to start by seeing how firm the seats are.
The comparison could reveal a problem.


The voltage at the supply terminal should be checked, however if the SAM detects an open cct after a short while, it may disconnect power.
Twelve volts might not be right.

[Edmonston33]

I seriously doubt that these will be made of leather.