Hi all, bit of a lurker on forums, so thought I would upload a guide for once as there doesn’t seem to be any info out there. I bought a leather interior with heated seats for cheap so set about retrofitting the electrics. I also got the seller to send me the switches with the plugs attached with about 10 cm of wire.
1) Cut off original connectors which are for heated seats and add any new male connector. I used these waterproof ones off ebay and soldered them on. Remember what order the wires are in. You need to connect to the positive, negative, sender for high heat and sender for low heat.
2) Disconnect battery as you will be messing with the SRS connection which will leave an error light if not.
3) Take out old seats and centre console cover. Screw on switches for seats.
4) Get the corresponding female connector and solder on 4 wires with the power and ground able to carry 20A. Tape it next to the SRS connector and then route it under the carpet and back up into the centre console.
5) Use piggyback fuse blocks to take a feed from 28 or 29 for the one that says number 5 on the diagram. Number 5 is for heated seats in the fuse box, so as these were not installed from the factory it isn’t present. 28 and 29 are for the cig lighters. Piggyback off 36 too (which is present). Route the power wires to the centre console.
6) Wire up as per wiring diagram, noting that the high and low heat are back to front on the diagram. There is only 7 wires to connect, if you don’t bother to connect the wiring for the switches to be illuminated when the lights are turned on. They will still have the power LED when they are the seats are turned on. Ground the earths to any suitable point.
7) Bolt down seat and plug in. Do same on other side. Reinstall centre console.
Hopefully someone will find this useful
Car looks good with a leather interior now.