Z4 retro fit heated seats.

[Z Victor 1]

My 2004 Z4 does not have heated seats. Looking into this I have been told that pre facelift Z4 s have the correct wiring for the heated seats even if they were not fitted. Is this correct? Also , are all heated seats electrically operated as well, ie; back rest movement etc or are some just heated, but manual operation? Any information for this job very welcome.
Ken.

 

[philiper]

What is your manufacturing date? This post on Z4-forum will be a good starting point https://z4-forum.com/forum/viewtopic.php?t=24819

I installed electric/heated m sport sears on my E85, my car had manual heated seats! The new ones were electric so due to car being early 2004, it was just plug & play

 

[Z Victor 1]

Thanks, that's brilliant.

 

[Z Victor 1]

Looking at the specification I printed off my car was built in July 2004 so not sure what wiring it has. Also, the spec details say automatic transmission, but it's manual. That's from ; bimmer.work:VIN Decoder for BMW

 

[Z Victor 1]

Looked on a different site and the specification comes up with alternative transmission details, auto or manual for my 'chassis' number. Everything else seems correct and the build date on both sites is 13/07/2004. Would this be before or after changes to the wiring for heated seats ?

 

[Z Victor 1]

This may seem a stupid question to anyone who knows anything about 'motor electricals' ( electrical stuff a bit of a mystery to me!), but apart from the build date, how can I tell the difference between a car with the correct wiring and a later one without?

 

[philiper]

From memory I think it was pre-wired till Oct 2004 and then stopped!

 

[t-tony]

Usually any “unused” wiring is tied/taped back safely out of the way. You may need to remove the seat and possibly lift the carpet to see it the wiring is there. The wiring for the C/C switch is taped up and it’s only about 2” long.

Tony.

 

[Z Victor 1]

Thanks Tony, will take a look.

 

[Z Victor 1]

Back in the old days when it was 50/50 or less that the car would start in the morning and I spent more time under my cars than driving them there were no electrical wires connected to the seats. So in my ignorance I'm wondering why there are connections to my seats when they are completely manually operated? They look the same as the ones shown in the Z4 forum post kindly mentioned by @philiper.

 

[philiper]

Airbag connections maybe, occupancy sensors

 

[gookah]

seat belt tensioners and occupancy sensor

 

[Z Victor 1]

Thought it might be to do with airbags, but I didn't know anything about occupancy sensors on seats until I read the article you referred to on Z4 forum. Sounds like on that car one was fitted to one seat not both, is that normal?

 

[philiper]

Yeah normal, as the driver will be in the car but the seat needs to know if there is a passenger present or not, hence the occupancy sensor under the cover

 

[t-tony]

The seat belt pre tensioners fire a split second before the airbag fires to keep you back in the seat as the airbag inflates.

Tony.

 

[Z Victor 1]

You learn something everyday, especially when you know nothing to start with.

 

[Z Victor 1]

After crawling about looking under my seats to see what was there I decided to fit my new 3rd brakelight as it was relatively warm this afternoon. The old one had a bit broken off the end when I bought the car. Bit of a fiddly job as the old one didn't want to come out.It seemed to be stuck in and yet there were no signs of any sort of sealant or adhesive when I got it off, but literally had to break it to get it out. Also on mine it was necessary to take off the little back panel to access the connector which was a little stubby branch on the lighting cable.This also taught me that by removing both back panels fitting the springs and nuts to attach the new light was much easier.

 

[Bigwinn]

Hi mate

I retrofitted heated and electric seats to my last z4, if I can help let me know- write up here

After crawling about looking under my seats to see what was there I decided to fit my new 3rd brakelight as it was relatively warm this afternoon. The old one had a bit broken off the end when I bought the car. Bit of a fiddly job as the old one didn't want to come out.It seemed to be stuck in and yet there were no signs of any sort of sealant or adhesive when I got it off, but literally had to break it to get it out. Also on mine it was necessary to take off the little back panel to access the connector which was a little stubby branch on the lighting cable.This also taught me that by removing both back panels fitting the springs and nuts to attach the new light was much easier.

hi bud

I did a heated and electric seat retrofit to my last z4

I’ll send the write up but if I can help let me know

stuart

 

[Bigwinn]

Hi mate

I retrofitted heated and electric seats to my last z4, if I can help let me know- write up here

hi bud

I did a heated and electric seat retrofit to my last z4

I’ll send the write up but if I can help let me know

stuart

How To- Retrofit Electric/Heated seats - Z4-forum.com

 

[Z Victor 1]

Hi @Bigwinn, Thanks for sending all that. I had decided to shelve this for the time being. The decent seats I saw advertised were pretty expensive and we only normally use the car with the top down when it's not too cold so I questioned the value of doing it. Then again if I saw some seats at a good price I might change my mind.