Heated seat wiring diagram??

Hi all, ive just joined tonight after i bought myself a brilliant Mk1 cabriolet Rivage from a close friend.

To keep it short and sweet, ive got a few jobs to do here and there on it to get it in full working order but one of those is the heated electric seats and i need a wiring diagram for it to clear things up.
They are all wired up and the relays under the seats work fine (tested with a 9v battery). The switch works fine aswell with a multimeter and im getting 12v to the relay base with the ignition on but the switch isnt energising the relays.

There is nothing obviously wrong except i am getting Mohms across what i think is the elements, but i cant know for sure unless i have a wiring diagram.

Would an open circuit across the elements still stop the relay from kicking in??

thanks Brad

Heated elements can be open.
But the relay is a controller and I'd have it out and have a look see. These tend to corrode on the inside and become no good.

I have had the relay/controllers out from under the seats. Passenger side has a bit of moisture in it but they still worked ok with a battery. I can only assume the circuit it broken through the elements?

I think the back and seat elements are in series too.
I thought I had a diagram, but it looks different as it mentions motor control units too. I know the Corrado has the same set slightlty different control knob.

have a look in my sig, jetta89.pdf page 10. ok its a pre-90 mk2 jetta, but the wiring for the heated seats is the same

you could try swapping the under seat controllers over. See if that makes a difference they are the same. But they suffer from internal corrosion.

Thats brilliant i have found it. Thanks very much, its just what i needed. Now i can double check across the right colour wires 

Thanks for the pic Chortle. I had a look yesterday and tested them electrically and they were fine. Whilst they are open im going to clean the n/o contact with cleaning strips at work. Shines the contacts right up

have a look at mine just to dark let you no in the morning
if it will help

I think one of mine is stuck on as the seat is permanently on on the drivers side.
No matter if  it's switched down or off?

It's a summer job especially when I don't need them lol.

I've got a spare relay in the shed somewhere so it's no biggie I guess, undo the acorn nut off the front tilt seat back to get underneath. If  it's dry tomorrow may have a look see.

If its constantly on then youd think it was the temperature sensor thats failed and isnt cutting the relay off but if its still doing it with the switch off then the relays probably stuck in the on position? That or a short in the circuit board maybe? 

Oh the joys of electrickery

yep could well be the thermistor.

Just didn't want to strip the seats down yet.
I need a good sunny day.
No excuse really not to have a proper look see.
Maybe tomorrow? Need to get into my sheds and dig through  my gear.

Can you let me know how you get on removing the leather and stripping down the seats?
i had a quick go the other night and it was getting tough to stretch the leather over the frame to get a good look in

So ive had a little play about tonight and ive got 12v onto the relay/controller base for the heater elements but im not getting anything for the switched 12v that goes onto the dial switch on the dash. 

Can anyone help, maybe rubjonny?

Ive checked the diagram from you pdf files and the colours dont match but thats ok because ive worked our whats what but i can find the exact fuse supply

checked the fuses? seats go to G/3 fuse 12 and switch to A/22 fuse 13 if the cab is the same as a pre-90 mk2.

if its a bit different just check all the fuses tbh see if any have blown. to start with look at 12,13, 17 and 18 these are your usual suspects

Ive sussed it all finally. Turns out the supply is through the headlight switch. Only found out by checking for power at the back of the seat switch lamp connections after i turned the headlights on to check the bulb.

I ended up taking the seats apart aswell and resoldered the broken temp sensor connections and the heater elements. Got some pics so thinking of doing a quick how to guide? was a doddle

that aint right! unless you mean you wanted the power for the little bulb in the switch?

1 - grey/blue - dash illumination (not sure why this is black on the jetta89 diagram!!)
2 - brown - earth for illumination  
3 - black or black/yellow - ignition live - A/22 or a G spade
4 - black/red - driver seat relay pin 6/P
5 - red/white - driver seat relay pin 5/86
6 - yellow - passenger seat relay pin 5/86
7 - yellow/red - passenger seat relay pin 6/P

wires to the seats may differ in colour!

Yes thats what i was checking, that the little lamp inside of the heated seat switch was working ok, but the black wire (ignition live), i think, which is next to that pair was what i found to also have 12v on it now that the headlights were on and subsequently feed the power down to the controller/relay.

The circuit works fine but i just need to re-wire it so the igniton live isnt going through the headlight switch

Good work so get some pics up. I did a seat refurb in the how to section that shows how the covers come off.

Decided to have a look see at mine and both were beyond repair.
The problem is the position in the cross member  under the seat and in sponge too.

I had two spare from another loom so took them apart and thankfully they were good, gave them a clean with Electrical contact cleaner.

These were the state of those taken out.








The rust I tipped out……



Rekon I'm going to still have the seats apart for an inspection.

Yeah i will do Chortle. Its a shame that one of them just gave up after it tested ok a few times so i had to order one off german ebay. Should be here thursday

I will do asap. Working long later hours at the moment but its simple steps probably very similar to what you have already. Got some pics of the element soldered connections which should help people get them working again. Feel i should give something back after to the forum

Those relays are well and truly screwed arent they. Im going to waterproof mine i think once the new ones in. Try to save from a repeat event