Seat Heating not working

[Mark R]

Hi All, looking for advise/suggestions if possible. our 2007 2.5 si Z4 seat heating has failed on the drivers side, I understand this is a common problem. have had a look and both base and back elements are open circuit so guess both have failed.
Question - I know its a bit of hassle to do but has anyone changed the elements before ?, and if so anyone have a "how to" guide please.
Secondly and probably just as important can you get replacement elements ?
found this on the net and the switch looks the same as we have ? https://www.amazon.co.uk/dp/B0051BMMJ0/ref=asc_df_B0051BMMJ057816208/?tag=googshopuk-21&creative=22146&creativeASIN=B0051BMMJ0&linkCode=df0&hvadid=309828959236&hvpos=1o2&hvnetw=g&hvrand=17520469952419476860&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9045628&hvtargid=aud-548500765412la-561139568576
bit of a long link...... but any thoughts on these would be great please.

Thanks in advance Mark.

 

[MrPT]

I wrote a how-to on replacing seat foam, which included removal/replacement of the back heating element: https://z4-forum.com/forum/viewtopic.php?f=34&t=84093

I would also have assumed that open circuit = broken (based on fixing ovens etc!), but have you also checked the fuses, loom etc?

The fuse box connector is X11004 (for both driver's and passenger's sides) and the pins are:
* 10 - driver's power, fuse 29
* 5 - passenger's power, fuse 15

There are some pics of the loom and fuse box (from a 2.5si, incidentally) here: https://z4-forum.com/forum/viewtopic.php?p=949435#p949435

 

[Mark R]

Hi MrPT, thanks for the reply and the link.
I perhaps should have added that I have power (11.7 volts to be precise) to both connectors under the seat.

 

[Mark R]

Further question guys/gals, I have seen somewhere (or thought I did) on here a link to check options fitted at purchase, could do with checking to see if my seat heaters are aftermarket or factory fit.
Anyone have a picture of the OEM seat heater switch pls, mine are the 2 position rocker type switch as in the link in the original post.
Thanks again mark.

 

[chrisgreen]

if they're a rocker switch - they're aftermarket.

OEM ones have a switch in the dash panel next to wear you put the roof down

 

[Mark R]

Hi Chris, thanks for the reply.
The switches are exactly where you state but the pictures I can find all look like press buttons with 3 little lights to the side of them

 

[chrisgreen]

yep - if it's a rocker switch it's definitely aftermarket.

OEM are the buttons with lights on

 

[Mark R]

Thanks Chris, That confirms it then, probably make it easier to replace.

 

[MrPT]

You can sometimes pick up heated non-sports seats for silly amounts of money (they've even been given away within this forum, if I recall correctly). The control panels come up quite often on ebay etc too.

 

[Mark R]

Thanks again MrPT, will have a look.

 

[Mark R]

Update, seat heating was indeed aftermarket, both drivers pads had failed (base and back) passenger seat all worked ok.
so I found this on the normal auction site it looked very similar to the ones fitted to our car so thought why not.

https://www.ebay.co.uk/itm/UK-2x-12V-Carbon-Fiber-Auto-Car-SUV-Seat-Heated-Pad-Heater-Heating-Mat-Warmer/153327922099?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Had to cut the connectors off the new one as they were slightly different so a little cut and solder job first, then 3 hours later heating pads fitted to both base and back and all is well again. Tricky job removing and re-fitting the leather but go steady be methodical and all is possible.

Ps think it has been said before disconnect the battery and do not re connect and turn ignition on until the seat pre-tensioner connect is re-connected or you will get a warning light that requires a good code reader to turn off.

Mark.

 

[MrPT]

Nice work!

Just in time for the snow...

 

[Mark R]

Thanks, Mrs R is now a happy bunny again.

 

[TimothyTub]

all of a sudden when my wift went to use the passenger side seast belt it wont unlock at all. does any one have any clues to solve this or am i looking to have to buy a new seat belt unit????