I'm in the process of swapping the seats from one 740 to another. While the "keeper" seats look great, the seat heaters never worked. I've traced the problem to the bottom seat heater grids on both seats, and taken the cover off the passenger seat. The wire at the point of contact with the thermostat appears to have burnt through. I'm guessing that the cloth (also burnt through) was meant to insulate the wire from the thermostat, but am only guessing.

Can anyone confirm that the seat heater grid is electrically insulated from the thermostat?

Enough wire has disappeared that I am skeptical that I could easily solder the remains and hope for a lasting fix. I can pull the working grid from the old seat, but that is a leather (keepers are cloth) and the incredibly useful FAQ reads that these are different systems.

Can anyone confirm that the leather heater grids are compatible?

Lastly, if anyone knows of a good source for replacement parts please let me know.

Thanks-

Dylan

I don't know of any difference between the leather and cloth seat heaters. You can bypass the thermostat too if you want but I wouldn't on the passenger seat. The driver's seat, I think you'll notice if it gets too hot. I'd just fit the leather-seat heaters to the new seats and go with it. If needed to make it smooth, some thin foam can be laid over the heater pad. You might also want to decide which seat has the better foam bottom in it, if there are an issues with that. Also, if the car the donor seats came from have the 3-position heater switches, the wiring for that's going to be different, so you might have to change things anyway.
Good luck keeping your ____ warm!
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total