Help please - wiring heated seats

[Fishy Dave]

Hello,

Myself and a fellow forum user are both in the same situation and could do with your help please.

- We have post 2006 Z4 Roadsters
- We are wanting to add heated seats to our cars which didn't come with them from the factory
- Being facelift cars the required additional heated seat looms are not present
- We have the switch panel with heated seat buttons

BMW used to offer a retrofit kit: http://www.realoem.com/bmw/enUS/showparts?id=BT92-EUR-09-2006-E85-BMW-Z4_M32&diagId=52_3032
This has been discontinued for some time now and I have so far not been able to find a copy of the installation instructions EBA 0301546. Judging by the cost of the kit (it was about £20) I am guessing that it consisted of wires and connectors only. I thought about visiting a breakers but don't know what I would need to remove from the donor car!

Trying to think laterally I noticed that the regular seat electrics for the BMW X3 and E85 Z4 have the same basic seat wiring loom 61117111903, therefore i wondered if an X3 retrofit kit could also be used 61110307620? I contacted a helpful guy from Dick Lovett Swindon who is looking to see if he can get hold of this part, but BMW Germany show one in stock only with a note that this part failed in testing!

So, this leaves myself and fellow forum user Marlon a bit stuck. Any electronics whizz able to understand the wiring diagrams (!) and make up custom looms for us in return for a bit of cash?! If not, does anyone still have a copy of the retrofit instructions they could share or maybe photos that might help?

Many thanks, Dave

 

[MrPT]

I've got the retrofit instructions: https://dl.dropboxusercontent.com/u/15374651/retrofit_heated_seats.pdf

 

[RJS-Z4]

I'd say that looks fairly do-able. It appears to just be cabling. You could make up a real rough version (no tucking under carpets etc) and check if it'll work on just one seat. Then actually knock a loom up or rip one out of a breakers.

The only thing that concerns me is the reference to coding it in? Should that be necessary?

 

[Fishy Dave]

Hi MrPT, thanks so much, that's a huge help, better than BMW UK so far in fact 8)

I've found the X3 heated seat loom retrofit kit for sale in the states, with images, wondering if it is the same or at least similar? https://www.ecstuning.com/Search/SiteSearch/61110307620/ES159521/

 

[Fishy Dave]

I think I've answered that, it is different according to the legend within the translated Monaco instructions I found! :? Not sure if it would be close enough to adapt through?

http://www.mbmw.it/istruzioni/pdf/307621.pdf

Should I track down a Z being broken or is their an electronics guru who can make something up?

 

[MrPT]

Hi MrPT, thanks so much, that's a huge help, better than BMW so far in fact 8)

No worries. Wish I could help more - I've done a few retrofits and made up my own loom for electric seats - but just a bit stuck for time at the moment.

It is very time consuming, but I would persevere with the wiring diagrams, if you can (assuming you can't find the OEM kit). They are more simple than they look! I don't think I'd attempt this without knowing exactly what was being plugged in, where. One accidental short and you could be stuffed, particularly with the seats because they use the full 12V feed for power and heating.

 

[Fishy Dave]

Thanks again, I'm determined to have heated seats eventually

Found the E46 heated loom diagram which looks pretty similar? http://www.angelfire.com/myband2/ds/heated_seats-English.pdf

 

[Fishy Dave]

A box from ECS tuning turned up today with the X3 retrofit loom included. I'm not going to have the time to take a look at it for a couple of weeks sadly, but assuming it can be made to fit I have the correct switch panel and wiring so just need the heat pads.

 

[Marlon]

A box from ECS tuning turned up today with the X3 retrofit loom included. I'm not going to have the time to take a look at it for a couple of weeks sadly, but assuming it can be made to fit I have the correct switch panel and wiring so just need the heat pads. How does the car 'know' it is connected to the heat pads? Does it read a certain resistance or current flow?

I will be watching this thread intently - fingers crossed you are able to sort it

 

[Fishy Dave]

Result! The X3 retrofit loom is broadly the same. Having spent the last hour or so checking between German and Monaco(!) X3 retrofit instructions and English Z4 instructions (thanks again MrPT) I labelled up all 14 connections and every one checks out, even the wire colours are identical.
The main differences are that the X3 loom is in two halves for driver and passenger plus I have a spare 'Kbus' wire which doesn't appear to be needed or used in the Z4. The next challenge will be to see if the cable lengths are acceptable, but as the X3 is not a tiny car I'm hoping it will be fine.
Feeling very positive that this could be a good way of retrofitting heated seats to our cars. 8)

 

[Marlon]

This is looking very promising Dave, I'm getting excited - keep up the good work

 

[Scooba_Steve]

Good work

 

[Marlon]

I've got the retrofit instructions: https://dl.dropboxusercontent.com/u/15374651/retrofit_heated_seats.pdf

Hi MrPT,
Could you check the link to your retrofit instructions please - I'm getting an error.
I need to print it off as we are hopefully getting nearer to a solution.
Many thanks

 

[Fishy Dave]

Hi Colin, I downloaded them from MrPT so have emailed you a copy.

 

[Marlon]

Hi Colin, I downloaded them from MrPT so have emailed you a copy.

Cheers mate

 

[Marlon]

Update:
Fishy Dave ordered me a set of these X3 wiring looms from the states, and very kindly labelled them up for me and then posted them on.
I now have the looms (and the switch centre) and have talked to my Indy this afternoon regarding fitting. He is happy to try it out and so I've booked in for the 6 April.
Fingers crossed the retro fit loom from the X3 will fit the Z4, and I can finally make use of the heated seats.

 

[mr.tourette]

Update:
Fishy Dave ordered me a set of these X3 wiring looms from the states, and very kindly labelled them up for me and then posted them on.
I now have the looms (and the switch centre) and have talked to my Indy this afternoon regarding fitting. He is happy to try it out and so I've booked in for the 6 April.
Fingers crossed the retro fit loom from the X3 will fit the Z4, and I can finally make use of the heated seats.

good luck pal... hope its goes well

 

[Marlon]

Update:
Fishy Dave ordered me a set of these X3 wiring looms from the states, and very kindly labelled them up for me and then posted them on.
I now have the looms (and the switch centre) and have talked to my Indy this afternoon regarding fitting. He is happy to try it out and so I've booked in for the 6 April.
Fingers crossed the retro fit loom from the X3 will fit the Z4, and I can finally make use of the heated seats.

good luck pal... hope its goes well

Cheers Steve

 

[mr.tourette]

Update:
Fishy Dave ordered me a set of these X3 wiring looms from the states, and very kindly labelled them up for me and then posted them on.
I now have the looms (and the switch centre) and have talked to my Indy this afternoon regarding fitting. He is happy to try it out and so I've booked in for the 6 April.
Fingers crossed the retro fit loom from the X3 will fit the Z4, and I can finally make use of the heated seats.

good luck pal... hope its goes well

Cheers Steve

:rofl: just in time for summer too :lol:

 

[Marlon]

good luck pal... hope its goes well

Cheers Steve

:rofl: just in time for summer too :lol: