Heated seat issue

[SR123]

So... after days of tracing cables, I eventually managed to get the heated seats working.

The problems I discovered:
As previously deduced, the loom that was fitted was for seats with a single heated seat controller. The seats that I had both had a controller so wasn't compatible.
Some of the wiring into the AC module wasn't correctly configured and the module had no power supply.
The original retro installer hadn't used the existing (correct) fuseways - and the fuseways used didn't have fuses in them!
There was no ground connection... at all!

I suspect the installer had a plug and play kit that they very neatly installed without actually understanding what they were doing.

I was only able to sort this with the help of VAG-Abound, Ste81 and going back to basics with a wiring diagram. The only issue I've found is that the seat pad on the drivers side doesn't work - the lumbar and back pads work fine though. The passengers side is fine. The job to replace the element or swap the seats pads looked way too difficult, so I'll live with it as is (unless someone knows of a easy method?!)

[Ste81]

Glad you sorted it mate. Yes it will be a nightmare stripping seat down to change the element you might be better of just getting another drivers seat from a scrapper and straight swop it

[VAG-Abound]

Excellent - I was wondering how you were getting on.

Did you end up lifting the floor liners to fix those things, and so put in new cables where needed as well? Or go for the two controllers under one seat approach which looked like it might work off existing loom?

[SR123]

It was easier to run the cable between the seats, under the dash as popping popping up a few lengths of plastic trim looked easier than threading cable under carpet! I kept both controllers in the end. Generally quite pleased with my handy work! Only mild disappointment was finding out one of the element pads is duff, but still a victory and it didn't cost me a penny!

Next task is to remove a defective aux heater...