It's right there on the first postRldee007 said:
https://www.keepandshare.com/doc2/119303/z4-retrofit-heated-seats-pdf-339k
Heated Seats Using E46 Retrofit Loom
- Thread starter Zulu4
- Start date
https://www.keepandshare.com/doc2/119303/z4-retrofit-heated-seats-pdf-339k
Zulu4 said:It's right there on the first postRldee007 said:
https://www.keepandshare.com/doc2/119303/z4-retrofit-heated-seats-pdf-339k
[/quote
Sorry I meant where you put that thermo resistor
Rldee007 said:
I put the thermister up against one of the carbon heating elements. I pushed the thermister in where the power cables go into the pad until it touched the first element.
One leg of the thermistor connects to earth, the other connects to the thin wire (white/green or white/blue in the above diagram, but may be differently coloured on your car if the wiring is already there). You can't really miss this thin wire as it is right next to the two thick heating power wires.
In the above diagram, you can see the thermisters on page 11 labelled "NTC" in the pads at X733 and X740
Ive wanted heated seats for a while and this has thread has brought it back to the top of my radar again Ive been saying for the last 5 years im going to do it.
Anyway I figured I would get the loom and make it up and then when there is a dry day I can fit it in the car and source some heated seats to trade my non heated ones in for.
So from this
To this,
I have cabled tied the brown seat wired to the ends so I can figure out where they are going to break out of the loom when I get near the car. Waiting for a dry day to have a tinker.
Ive been saying for the last 5 years im going to do it. Anyway I figured I would get the loom and make it up and then when there is a dry day I can fit it in the car and source some heated seats to trade my non heated ones in for.
So from this
To this,
I have cabled tied the brown seat wired to the ends so I can figure out where they are going to break out of the loom when I get near the car. Waiting for a dry day to have a tinker.
So it seems I have built my loom upside down 
I have the ends that goto the seat up by the centre console and the centre console ends by the seats so have to sort that out.
I do have a small problem that im hoping the forum will be able to tell me what im doing wrong, the red/violet cable doesnt seem to connect to pin7 of the centre console plug (neither end) and if you look at the plug it seems to have slightly different shaped holes. The one in my car is different to the one that is in the kit and the spare bit of loom that came with the centre console switches.
EDIT: I hope its just something simple for the red/violet cable I think I got the others sorted or will have in a few hours once I have peeled all the tessa tape off.
I have the ends that goto the seat up by the centre console and the centre console ends by the seats so have to sort that out. I do have a small problem that im hoping the forum will be able to tell me what im doing wrong, the red/violet cable doesnt seem to connect to pin7 of the centre console plug (neither end) and if you look at the plug it seems to have slightly different shaped holes. The one in my car is different to the one that is in the kit and the spare bit of loom that came with the centre console switches.
EDIT: I hope its just something simple for the red/violet cable I think I got the others sorted or will have in a few hours once I have peeled all the tessa tape off.
Attachments
So I managed to get the rest of the wiring in but still cannot for the life of me get the red/violet cable to fit. It really feels like im trying to put a circle in a square hole.
The right connector fits perfectly into Pin 1 of X11004 at the fuse board end, but cannot get either of the connectors to fit into pin 7 of X1869, if you see my previous post the holes on X1869 seem to be different shapes
I also made my own ground (Hopefully good) for the drivers side seat, The passenger one I had to extend up to the front earthing point as the studs didn't have nuts on them on the passenger side only cable holder things.
The right connector fits perfectly into Pin 1 of X11004 at the fuse board end, but cannot get either of the connectors to fit into pin 7 of X1869, if you see my previous post the holes on X1869 seem to be different shapes
I also made my own ground (Hopefully good) for the drivers side seat, The passenger one I had to extend up to the front earthing point as the studs didn't have nuts on them on the passenger side only cable holder things.
Righto I have been down to pester the guys at the parts counter to see what connector I needed. They wont advise as the part "Wiring Harness" 61116902951 "is not designed for the E85/Z4" so BMW wont help or advise on what connectors you need for liability reasons However what they will do is sell you a selection of connectors for you to figure it out yourself. Thanks Naz you the man!
So here is what I found out
Part number 61138364844 is the female end that fits the fuse box connector x11004 and also fits the "new" style centre console connector part number 61136954535
If you have the Old style Connector Part Number 61138380728 then you will need part number 61138369644 to go into the centre console end.
Old style connector with the square holes, The new style has a rounded bottom and flat top on the holes.
New Crimp and part numbers for the connectors (Old Style)
Wooo!!!! Heated Drivers seat!!! Now just need to do a deal to get a passengers seat.
For anyone who is looking to do this in the future I think you can avoid buying the Wiring Harness 61116902951 as you only need the Red-Violet cable from that and you can make it up yourself using the following part numbers and an appropriate crimping tool. If you don't care about the cable colour (its Red-White and not Red-Violet)
For the Old Style centre console connectors. Note same description but different part numbers for the crimp connectors.
Cable red-white 4,0 MM 61126940164 (Priced by the Metre)
Socket contact ELO-Power 5,2x0,63 61138369644
Socket contact ELO-Power 5,2x0,63 61138364844
For the New style centre console connectors
Cable red-white 4,0 MM 61126940164 (Priced by the Metre)
2x Socket contact ELO-Power 5,2x0,63 61138364844
However what they will do is sell you a selection of connectors for you to figure it out yourself. Thanks Naz you the man! So here is what I found out
Part number 61138364844 is the female end that fits the fuse box connector x11004 and also fits the "new" style centre console connector part number 61136954535
If you have the Old style Connector Part Number 61138380728 then you will need part number 61138369644 to go into the centre console end.
Old style connector with the square holes, The new style has a rounded bottom and flat top on the holes.
New Crimp and part numbers for the connectors (Old Style)
Wooo!!!! Heated Drivers seat!!! Now just need to do a deal to get a passengers seat.
For anyone who is looking to do this in the future I think you can avoid buying the Wiring Harness 61116902951 as you only need the Red-Violet cable from that and you can make it up yourself using the following part numbers and an appropriate crimping tool. If you don't care about the cable colour (its Red-White and not Red-Violet)
For the Old Style centre console connectors. Note same description but different part numbers for the crimp connectors.
Cable red-white 4,0 MM 61126940164 (Priced by the Metre)
Socket contact ELO-Power 5,2x0,63 61138369644
Socket contact ELO-Power 5,2x0,63 61138364844
For the New style centre console connectors
Cable red-white 4,0 MM 61126940164 (Priced by the Metre)
2x Socket contact ELO-Power 5,2x0,63 61138364844
Hi all,
I was hoping someone who has done work with aftermarket heat pads might be able to give me a few pointers/a bit of help?
My 05 Z4 had factory heated seats (manual). I have purchased a set of manual sports seat without heating. I’ve got to the point of stripping the seats, have put the aftermarket pads in place (look the same as the ones show further up this post). I’ve added a 10k thermistor to the end of the grey wire and then from that to the brown earth.
Get it all into the car and and the factory seat buttons light up for a couple seconds and then go out. Any ideas on where the problem could be - is is actually possible to pair up aftermarket pads with stock buttons?
Any view would be much appreciated! Thanks!
I was hoping someone who has done work with aftermarket heat pads might be able to give me a few pointers/a bit of help?
My 05 Z4 had factory heated seats (manual). I have purchased a set of manual sports seat without heating. I’ve got to the point of stripping the seats, have put the aftermarket pads in place (look the same as the ones show further up this post). I’ve added a 10k thermistor to the end of the grey wire and then from that to the brown earth.
Get it all into the car and and the factory seat buttons light up for a couple seconds and then go out. Any ideas on where the problem could be - is is actually possible to pair up aftermarket pads with stock buttons?
Any view would be much appreciated! Thanks!
Usel
Senior member
The grey wire has its own pin in the connector. It doesn't connect to ground. (brown wire)
Original seats have 3 wires
Brown
Green/purple
Grey
Brown and green/purple have spade connectors and grey is a pin connector with the black block.
Far left is the heated seat connector. You can see 2 spades and a pin connector all in a horizontal line:
Original seats have 3 wires
Brown
Green/purple
Grey
Brown and green/purple have spade connectors and grey is a pin connector with the black block.
Far left is the heated seat connector. You can see 2 spades and a pin connector all in a horizontal line:
Thanks for that Usel 
When stripping the old heated seat - from the under seat pin connector block did come a green/purple, brown and grey wire that ran up to the old seat heated pad (in the base of the car seat). The aftermarket seat pad only has two cables - one red and one black. I’ve wired green/purple to red, and then brown to the black wire. I had then read to follow the grey wire from the pin connector block towards the seat head pad and add a 10k thermistor to it, then from other end of the thermistor find ground. Apparently this is needed so the stock heating buttons get the right messaging back through the grey cable!?!
Would you know if that sounds right? Like I say, the lights come on and just go off. Reading the fault code is says something like ‘open circuit’
Cheers
When stripping the old heated seat - from the under seat pin connector block did come a green/purple, brown and grey wire that ran up to the old seat heated pad (in the base of the car seat). The aftermarket seat pad only has two cables - one red and one black. I’ve wired green/purple to red, and then brown to the black wire. I had then read to follow the grey wire from the pin connector block towards the seat head pad and add a 10k thermistor to it, then from other end of the thermistor find ground. Apparently this is needed so the stock heating buttons get the right messaging back through the grey cable!?!
Would you know if that sounds right? Like I say, the lights come on and just go off. Reading the fault code is says something like ‘open circuit’
Cheers
There are the 5 you describe above. I’ve soldered a pair of brown and green/purple to the seat base pad wires, then the other pair that come out of the connector block lead to a small two cable male/female connector for the back rest pad - I guess for easy disconnection of the back rest. I’ve cut the back rest head pad connector off and soldered that to the new back rest heat pad wires, then plugged it back together.
Sorry, in short - in effect separate wires run to base and back me seat pads. I think that is all okay, it feels its what to do with this grey wire that did run to some sort of thermostat/resistor in the older seat base heat pad….
Sorry, in short - in effect separate wires run to base and back me seat pads. I think that is all okay, it feels its what to do with this grey wire that did run to some sort of thermostat/resistor in the older seat base heat pad….
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