E36 seats into E30--heater connection

[TSI]

I've finally managed to swap in some E36 seats to replace my unsupportive comforts. Thing is, I want them to be heated! I've searched all over the net for this swap, but nobody seems to have wired in the heaters.

I see that the E36 seat (let's begin with the passenger) has four wires, two brown (ground, I assume), one white/yellow, one blue/yellow. I don't know what they connect to inside the car, though. I read that the two white striped ones are for the backrest and seat, but then what about the temperature switch and the constant 12v?

The E30 harness, for its part, consists of a yellow, a brown, a black/yello and a black/red. I couldn't find which one does what.

Any ideas/knowledge?

[E30NJ]

hook up a multimeter to them and see which ones do what voltage. then look at the oem e30 harness diagram and convert them over to the e36

[TSI]

Yes, but the two diagrams don't match up. Forgive my electrical noobishness, but my take is that the E30 has one wire for high, one for low temp, whereas the E36 has two separate circuits for seat+back and the temp is regulated externally by the switch (hence the two grounds). I'm starting to think I need E36 switches.

[hendrixvodu]

E30 heated seats work a little different then the e36 I noticed the way they work in e34 is to make the "warmest setting" they send power to both low setting wire and high ... I retroed some e34 switches in my e30 ... What it seems like your missing is the rest of the e30 harness I believe red/ brown and solid brown 12v and ground... That sends the power to the switches and distributes it to the seats ... I have a full e30 heated seat harness hanging around I can get you in a direction if you need help .... For the e36 harness you described 1 ground for each setting so 2 grounds one for high one for low and 2 heat settings 1 high 1 low varied from the switch

[TSI]

E30 heated seats work a little different then the e36 I noticed the way they work in e34 is to make the "warmest setting" they send power to both low setting wire and high ... I retroed some e34 switches in my e30 ... What it seems like your missing is the rest of the e30 harness I believe red/ brown and solid brown 12v and ground... That sends the power to the switches and distributes it to the seats ... I have a full e30 heated seat harness hanging around I can get you in a direction if you need help .... For the e36 harness you described 1 ground for each setting so 2 grounds one for high one for low and 2 heat settings 1 high 1 low varied from the switch

Yeah, that sounds good. Can you send pics?

[nowak18]

I'm in the process of doing the same set up. Subscribed for info. I'll post any additional info I find.

[Andy.B]

I'm in the same position. I have e36 seats and an e30 heated seat harness and switches. I haven't worked out merging them together yet. I had not examined the diagrams close enough to resize the seats were powered differently.