[swiftryanswift]

Firstly, my apologies, this has been discussed a lot over the last 10 years and i've done a lot of research, however people haven't shared their trade secrets. Not all of them at least.

I have an 2010 E91 SE, which has heated seats but no IDrive, I've bought some M sport, heated, leather, electric, memory seats. I want to retrofit them which I understand is possible, but i need a little help. They are from a Pre-LCI car so i need to swap over the airbag headrests.

Starting with my drivers seat, the wiring pins i have available are 1,5,8 & 9. The new seat has K Can, so has 2,3,4,7,8 & 13.

My plan so far is to
- merge pins 8 & 13 on the donor seat and connect to pin 8 of the existing harness. This gives me a ground.
- Connect pin 7 on the donor seat to pin 9 on the existing harness. This should give me bolster power.

It's just what i do with the remaining wires that i get stuck with.
What do i need to do, in order to wire in the rest?
I've attached a wiring diagram to show what is left.
I'm based in Cheshire if anyone wants to come and help? However i would appreciate any advice.

The wires on my harness are 1 PWM Heat & 5 Ignition Plus Heat.
On the seat i have 2 & 3 for the K CAN and 4 for Seat Heat Module.

I could live without memory seats if that simplifies things? But need the seat heating functionality.

Thanks

[swiftryanswift]

So further research has given me a strategy to try, but would 100% appreciate input from others

To keep my car connector the same, the work will be done to the donor seat harness
- Join Pins 7 & 4 together (Keep Pin 4 connector)
- Move Pin 4 to Pin 9 location (currently empty)
- Join Pin 13 to Pin 8 (Joint ground wire)
- Connect Pins 2 & 3 into a new Wire Terminal Connector
- Join new connector pins 2 & 3 to nearest K CAN H & L
- Fit the seat.

This will make pins 1 and 5 on the cars existing connector redundant, but as the K Can should be passing the signal for the heat seating that should be okay? Fingers crossed.

[Red Racer]

https://www.e90post.com/forums/showt...+seat+retrofit

I used this thread in the forum to help me... good stuff...

[Red Racer]

The LED module I originally used started to give me issues. So, I went back and re-worked the solution. I started with a timed relay module...

https://www.amazon.com/dp/B07T3KCQZB...roduct_details

This allowed me to program the relay to turn on for 3 sec and turn off for 3 sec. I found that at 5 sec, then 4 sec intervals didn't re-activate the seat module. 3 sec seems to work continuously. It also gave me a higher amp rating which is where LED relay was failing.

Keep in mind this relay module is for 12v options and the seat only likes 5v. So, after the relay, I reduced the voltage to 5v by using a common Buck regulator set for 12v to 5v. There are many options out there... This is the one I picked.

https://www.amazon.com/DROK-Electric...758521&sr=8-17

Now the seat works continuously without any issues. Hope this helps.