View Full Version : Help me fix my heated seats!

02-04-2009, 01:37 PM

Since winter is almost over, its time for me to fix my heated seats.

what i know so far:

-Switches dont light up.
-Switches have been tested with known good switches, still nothing.
-fuse has been tested.

so, relay? Where is it? I just spent 10 mins staring into my fusebox and didn't find the heated seat relay (61311373585 p/n), but then again i'm a bit of a space cadet today.

02-04-2009, 01:44 PM
maybe the P/O swapped your heated seats out *th-up*
If you check
it shows a relay # 4. Its probly under the dash near the seat harness connection

02-04-2009, 01:46 PM
i've been looking for it! I can't seem to find it, but i got cold after a few mins. Will go back out there.

Its possible that the seats are swapped, but i doubt it. Plus, even so, the wiring diagram shows the switches are before the heater elements in the seats, so shouldn't they illuminate regardless?

02-04-2009, 02:09 PM
one of my drawings shows power comes from Relay K5 through Fuse #16. The Relay also enables power to the power sunroof and windows through Fuse 17.
If the relay is gone or buggered, your sunroof and windows shouldnt work.
If you want I can send you the drawings I have from the 1998 Mitchell Repair Manual

02-04-2009, 02:10 PM
^^if its not too much trouble. Crank sunroof ftw, windows work well though.

But the K5 relay isn't the heated seat relay itself, is it? Because afaik that's a different p/n

02-04-2009, 02:28 PM
no, from my drawing, it looks like it is shared with the windows.

But easily enough if you have a meter handy, pull out one of your switches and check pin 4 for 12V versus Pin 3 for GND. If these are good then you should have a light come on.

If not, it could be possible the connector for the seats has become disconnected or cut. Or you're sitting on unheated seats. To check that, its not too difficult to check under the drivers seat for the harness connection.

02-04-2009, 03:18 PM

Did as you suggested, the heated seat plugs aren't recieving any power (at all).

The seats are heated, and the connectors are plugged in under the seats.

02-04-2009, 03:19 PM
the heating pads can be damaged and the circuit is not closing - similar problem happens to heated floors in homes.

02-04-2009, 03:22 PM
^^right, but i've asked around. it seems when the heated seats burn out in e30's, the light on the switch still works. That leads me to believe that its not the element (also, since the switch isn't recieving any power, its likely that its an electrical issue)

02-04-2009, 03:30 PM
well in the Haynes manual the basic drawing is on page 12.26, ref. page 12.25
shoot me your email and I'll send the draings I have from the mitchell manual

02-04-2009, 03:37 PM


(msn is itarnawsky@gmail.com)

02-04-2009, 04:05 PM
emailed the manual

check for 12V at your fuse

02-04-2009, 04:06 PM
^^how do i know which side i'm supposed to test on? I know i can do both but just curious.

(go do this in a few mins)

02-04-2009, 04:11 PM
try both. If it has labels like 1 and 2, start with 1

02-04-2009, 05:31 PM
So, Thanks to Supernaught's help, i fixed it.

Checked for power at the fuse (car was running). Nothing, then suddenly when i touched something it spiked up to 13V.

Loosened the bolt on the fusebox, blablabla, reconnected the frayed wire, got in the car.


Then i think, hmm, mabye i should try the switches greg gave me?

Bam, both of them work.

All 4 elements work, the heat is amazing, they're better than my e36 heated seats (which obviously i never use cause its a summer car)

Thanks everyone, especially furyriderX and supernaught!

02-04-2009, 05:35 PM
no problem, good work *th-up*