Heated Seats Using E46 Retrofit Loom

[DMike]

The rear tab is similar, but angled 45 deg and thus you need to press down and forward there. When I did mine ages ago, I think I had done the bottom tabs first, which gives the trim more play when you undo the upper edge ones.

Pm sent.

[Zulu4]

Worked nearly all day on the driver's seat. I had a real result since when I started to take the leather off the backrest, I discovered someone in the past had replaced it with a heated seat backrest and cut the wires off, so all I had to do was solder some wires back on.

Then I inserted the aftermarket element into the seat base.
I found I could get the hog rings back in OK at the edges of the seat, but had to use tie wraps for the seam that goes across the seat base.

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Here's the wiring all complete with my connector block to the left of the BMW one.

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After refitting the seat I went for a test drive with a lovely warm bum and back. I'm quite chuffed with myself.
And many thanks to the guys on this fantastic forum that helped me do it.

[Zulu4]

For anyone attempting this, some tips for the hog rings:
To remove them use a pair of long nose pliers , get them inside the hog ring then pull the handles apart to stretch the ring open. Then you can rotate the ring to free it from the seat and leather.
To re-insert the hog ring, set it up so that there is a gap of about 3-4mm, place it into the leather first then, using fingers or pliers, fit it to the seat. Then use the long nose pliers to squeeze the ring closed. (I was going to use hog ring pliers, but the long nose pliers work fine.)

[NewToZ4]

Buy a centre console switch panel with heated seat buttons and swap it over with the existing one.
To do this, chock the wheels, put the car into Drive (Automatic) or 6th (manual) and switch the engine off. Disconnect the battery. Remove the screw at the bottom of the ashtray and pry it and switch unit out together, starting at the bottom. Use a soft cloth to protect the centre trim as there are sharp parts on the bottom of the ashtray.

Hey! so in testing my seats, i want to be sure that theres no break in the wire before i get a new center switch, as I think mine has failed. Regardless, do you remember which plug was for the heated seats in the switch? my goal is to test continuity on the wire for the places that I can't see and or easily get to, so to use the seat plug and the pin on the connector to test for breaks. Any help you can give would be greatly appreciated!
EDIT: Found via instructions you sent me

[Rldee007]

@Zulu is possible to show a wiring diagram, even if it is hand drawn?

[Zulu4]

@Zulu is possible to show a wiring diagram, even if it is hand drawn?

It's right there on the first post

https://www.keepandshare.com/doc2/11930 ... s-pdf-339k

[Rldee007]

@Zulu is possible to show a wiring diagram, even if it is hand drawn?

It's right there on the first post


https://www.keepandshare.com/doc2/11930 ... s-pdf-339k
[/quote

Sorry I meant where you put that thermo resistor

[Zulu4]

Sorry I meant where you put that thermo resistor

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

[Usel]

For anyone who reads this excellent guide and is fitting aftermarket heat pads then the following part numbers will be useful for you:

Black connector block 61138369713
Order 2 x spade pin 61138364835
Order 1 x pin for thermostat/thermistor wire 61131393723

[Matty_Z4]

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

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To this,

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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.

[Matty_Z4]

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.

[Matty_Z4]

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

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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.

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[Matty_Z4]

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.

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New Crimp and part numbers for the connectors (Old Style)

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Wooo!!!! Heated Drivers seat!!! Now just need to do a deal to get a passengers seat.

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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

[Zulu4]

Well done Matty
It's like doing an electrical jigsaw isn't it.

[Matty_Z4]

Well done Matty
It's like doing an electrical jigsaw isn't it.

Thanks man, it is just like Adult Lego Follow the instructions and plug it all together