How do I hook up heated seats?

[trashcop 80s 80s]

I searched but didn't find anything. I just got a pair of heated sports seats out of a cabrio and wanted to know if there is an easy way to hook them up. Is the wiring already there in an 89 325i? I have the switches but I didn't get any of the wiring, but I could go back and get it if I need to.

[Jarvis]

PM DanGillan. He's the only person on this forum that I know of that has retrofitted heated sport seats into a car that did not originally come with them.

[e9nine]

I put stock heated seats in my 88 325 by doing the following process. I didn't use any relays and I am not aware of a relay for heated seats. I replicated the setup from my '90 325iS that came with heated seats:

-- Remove the front and rear pieces of your center console.
--The front is held by 1 plastic screw on each side in the foot wells and a plastic screw which you have to expose by removing the shift boot.
--In-between the pocket infront of the gear lever and the heater console there is the last nut that you have to unscrew.
-- Disconnect all switches and wiring that are in the console. i.e window switches, circuit breakers etc.
-- Proceed to unhinge the front console from the rear and pull it out.
-- Remove the rear console by taking the ashtray out, unscrewing the plastic screw you see and pull it out gently. Now is a good time to replace your ashtray light if it's out.
-- Swap over your new rear cluster with the switches
-- Remove your knee bolster.
-- To the left of your clutch pedal around "10-o'clock" you will see a power block.
-- Locate the second pin from the right in the top most corner.
-- Insert a 15amp Fuse in fuse slot # 16
-- This pin should have a positive voltage that you SHOULD verify with the fuse in and out.
-- Proceed to tap into the prong with an appropriate connector
-- The rest is pretty much self explanatory...locate your ground and you're good to go.

[trashcop 80s 80s]

So, I need to go back and get the connectors to the seats and to the switches with all the wiring.

[fporro]

i just retrofit it a set into my cabrio.
as e9nine said and ...

- remove inner door sill
- remove hood release handle and driver side kick panel
- peal carpet from back to front as far as fronts studs that hold seats.
- run harness to passanger side, then to driver side.
- run power and ground (all) cables across and in FRONT of seat studs
otherwise seat rails will crush them and short circuit (pls don't ask how i know)
- ground will be just above steering column shaft where all the others attach to.

here's a pic of an extra harness I have and finish product...

White/red - 12V with ignition switch in ACC mode
Brown = ground
2 white/4 female connectors for seats and
2 black/4 female connectors for switchs

[Court M3]

how much for the extra harness? :)

[fporro]

how much for the extra harness? :)

sorry, but it's going into my other cabrio.

it's very easy to duplicate, basically Positive and Negative split to power the switchs and from there continue onto seat plugs as Power, Hi & Low signals and Ground., no relays at all.