Old Library

By request that it be added here, here's my writeup on adding heated seats to your MKIII.

Parts List [I]Here's the parts you probably don't have:[/i]

1H6 963 563 - Heated Seat Control (The switch) 1HM 971 381 B - Harness for Heated Seats (One of two you need. This one plugs into the switch and goes to the other harness.)

1HM 971 381 C - Harness for Heated Seats (This is the long one that goes from under the dash to the seats.)

[I]Parts you may or may not have: (Check your seats.)[/i]

1H0 971 382 (Quantity 2) - This small harness is actually on the seat itself. it has a relay holder and connects to the heating element. One for each seat is needed.

161 919 533 (Quantity 2) - This is the relay needed for each seat. If you didn't have the above, you probably don't have this.

1H0 972 595 B (Quantity 2) - Bracket for the relay. Wire ties would probably work, but this is **SLIGHTLY** less trailer.

N 016 194 3 (Quantity 2) - Pop rivet for above relay bracket. You may need a rivet gun for this, I don't know. The seats I did had all these parts installed already.

The Labor:

Ok. Now that you have ordered all your parts and have them in hand, it's time to wire up your seats. You will note that both harnesses have wires coming off of them going to single flat connectors. The harness that plugs into the heated seats switch has a gray wire coming off of it, and the other longer harness has a black and white wire and a brown wire (IIRC.) These all plug into spots that exist on the car, so it's actually a pretty easy mod.

1. Remove negative battery terminal. (PLEASE do this! There is serious potential to damage the instrument cluster if you don't!)
2. Remove the lower fuse cover panel.
3. Next remove the instrument cluster - Remove headlight switch, Remove dummy panel by radio. Unscrew two screws around bezel. Using a long phillips, then remove the shroud around the ignition switch. (You will probably need to get on your hands and knees to position the screwdriver properly.) Remove the bezel around the instument cluster. Remove the two screws on either side of the cluster and pull the cluster toward you (It's hinged on the bottom.). Remove the electrical connectors on the cluster and pull the cluster up and out of it's hinges. Set aside. Shine your flashlight in the dash. Off to the left, you should now see some terminal blocks that coincedentially match the color and shape of the terminals on your heated seats harness.
4. Take the short harness (1HM 971 381 B) and plug the grey flat connector into the terminal block with the other grey wires in it. - This is the illumination circuit. If you need to make sure you have the right one, reconnect the battery and the headlight switch. Take a multimeter and test the voltage on this post while moving the dimmer up and down. If it drops and raises with the dimming, you have the right circuit.
5. Route the harness behind the plastic peice you removed next to the radio and connect the white connector into the heated seats switch. Let the other connector hang in the dash for now. (Don't put the switch in right now, you need to put the cluster back in!)
6. Take the long harness (1HM 971 381 C) and plug it into the short harness coming from the switch.
7. Take the brown connector and route it through the underdash wiring to the brown "wheel" looking thing on the left side of the car. - This is your ground connection. This wheel looking thing should have LOTS of open slots on it for ground. It's a real tight fit to get back there with your hand and remain dexterous enough to get the connector in there, but it can be done.
8. Find the green terminal block by the instrument cluster and get the green connector in the vicinity of the terminal block. - It's easier to get it there from under the dash, then reach in through the top of the dash and connect it. You may want to verify that the green terminal block is live only when the key is on using your multi meter. It should be this way, but I did verify this. I had no instructions to follow along with either.
9. Take the green connnector (Black and white wire) and plug it into an open green terminal on the terminal blocks by the instrument cluster. - I found it helped if I stuck my hand in the headlight switch hole and connected it up that way. For some odd reason, these flat connectors seem to want to fit in some of the holes but not others. In the car I did, the green terminal on the left end of the block was open. I used that.
10. Libations for all involved. - Have a frosty beverage. I'm sure the frustration level from working under the dash is getting to you. Now this is where it gets tricky. When we did this project on my buddies car, we didn't feel like ripping up the carpet to hide the wiring harness. When I do mine, I'll probably install the harness when I change carpet colors. If you want to tear the carpet up, you are on your own as to how to do that.
11. If your seats don't already have the harness connected to the them that connects to the heating element and the relay, install this now. It's pretty self explanitory once you get under there (Two connectors and the relay). You will probably have to take the seats out to do this.
12. Route the cable along the center console to right behind the shifter mechanisim. - You will probably want to move the rear part of the console back, so do this by removing the two phillips screws on either side of it. They are covered by two trim peices that just pop off. Remove the screws and pull the console back. The distance you can move it will be limited by the boot on the E-Brake. (Don't worry, this is enough.)
13. Route the shorter of the two connectors on the harness to the drivers seat and plug it in. - Be mindful to allow enough slack for full motion of the seat.
14. Route the remaining connecter over the center console to the passenger seat and plug it in. - You will probably have some slack, so wire tie it up.
15. Replace the rear center console, being careful to not pinch the wires for the heated seats.
16. If you haven't already, reconnect the battery negative terminal and test the heated seats. You don't need the cluster in, just connect the battery and start the car. The seats will work if you don't start the car, but they seem to work a lot faster if the voltage is up from the alternator running. (Note to TDI'ers: You DO need the cluster plugged in, or you will trigger a DTC for a missing glow plug indicator. No big deal if you have a VAG-COM) Don't forget to test the dimming of the lights on the heated seats switch.
17. Libations for all - Now that your arse is nice and warm, take a break. Enjoy the heated seats.
18. Disconect negative battery cable and replace the insturment cluster and all related dash trim. Don't forget that horrid panel that covers the fuse panel.
19. Libations for all - You're done! Know that you will no longer freese your arse off on those cold winter mornings!!!!