Heated seat installation

carl4u44 · Feb 23rd, 2010, 18:00

Hi folks, OK well I replaced my 440td with leather seats a while back. They had black plugs on the bottom which I have attached to the black plugs coming from the car floor. The driver seat had two plugs coming from the floor (red/white, brown/black) and the passenger seat one plug (green/brown).

Anyway, installed the twin switch on the dash but the seats are not heating. I'm going to test the current from the floor plugs shortly but is there anything else I need to look out for?

The car never originally came with heated seats. The passenger floor plug needed to be dug out from under the carpet where it was factory set there.

Further to note there was also two brown female spade wires tucked under there as well, they look like power leads to something...

Any ideas????

B20F · Feb 23rd, 2010, 19:01

The brown spades could be the safety belt warning. Just check which gets 12v when you use the heated seat switch. If still the seat heater isn't working the heater mat under the leather clothing is gone. A very common fault. Easy to repair with a soldering gun, not so easy to get at. You have to remove the leather to get at it. It's doable, but takes time. Best is to remove the seat and take it inside to work at it in a nice warm room.

carl4u44 · Feb 23rd, 2010, 19:41

Many thanks on that b20. I'm actually thinking those brown spade wires may be to do with the heated mirrors on some models. Anyhow I shall get on with checking the 12v current tomorrow in better light.

Having read the older posts im wondering if an outside temp sensor or cem might have something to do with it....Or perhaps I may strike lucky with this 'plug and play' option im trying at the moment! As long as im getting power to the seats then I shall take on the 'seat mat challenge'.

B20F · Feb 24th, 2010, 11:32

The CEM and outside temp.sensor have nothing to do with the seatheating as far as I know. The heated seats have a thermostat built in to keep the seats from overheating. They keep the temperature from the seats at skin temp. that's around 25c iirc. If the mats are not repairable you can get generic heating mats at an automotive store to replace the originals. Those get warmer then the originals.
Another option for these connectors may be for the SRS belt tensioners. Good luck hunting for the culprit!

carl4u44 · Mar 8th, 2010, 10:22

ok well there is power getting to the seats but the seats are not heating. Im guessing im going to need to repair or replace the element inside. As mentioned earlier in the post, the second wire to the drivers seat actually controls the seat belt clicker! The two single brown wires tucked away seem to be for the seatbelt tensoners but im wondering why they never showed up on the srs light to begin with!

B20F · Mar 8th, 2010, 20:30

Quote:

The two single brown wires tucked away seem to be for the seatbelt tensoners but im wondering why they never showed up on the srs light to begin with!

Probably some PO removed the bulb?

carl4u44 · Mar 9th, 2010, 08:30

Sorry, the bulb lights and the system works - just never showed as a fault on the diagnostics side. I remember installing those seats a while back, looking at 'the tensioner/seat belt charges'.... no electrical wires were ever plugged into them and even on the removal of my older seats..

Perhaps on the 400 series it was an added luxury upgrade to have the seat belt tensioners!

Feb 23rd, 2010, 18:00	#1
carl4u44 Master Member Last Online: Sep 7th, 2023 17:21 Join Date: Feb 2009 Location: kk	Heated seat installation Hi folks, OK well I replaced my 440td with leather seats a while back. They had black plugs on the bottom which I have attached to the black plugs coming from the car floor. The driver seat had two plugs coming from the floor (red/white, brown/black) and the passenger seat one plug (green/brown). Anyway, installed the twin switch on the dash but the seats are not heating. I'm going to test the current from the floor plugs shortly but is there anything else I need to look out for? The car never originally came with heated seats. The passenger floor plug needed to be dug out from under the carpet where it was factory set there. Further to note there was also two brown female spade wires tucked under there as well, they look like power leads to something... Any ideas????

Feb 23rd, 2010, 19:01	#2
B20F Master Member Last Online: Jul 7th, 2016 21:43 Join Date: Mar 2007 Location: Zeist View Photos By: B20F	The brown spades could be the safety belt warning. Just check which gets 12v when you use the heated seat switch. If still the seat heater isn't working the heater mat under the leather clothing is gone. A very common fault. Easy to repair with a soldering gun, not so easy to get at. You have to remove the leather to get at it. It's doable, but takes time. Best is to remove the seat and take it inside to work at it in a nice warm room. __________________

Feb 24th, 2010, 11:32	#4
B20F Master Member Last Online: Jul 7th, 2016 21:43 Join Date: Mar 2007 Location: Zeist View Photos By: B20F	The CEM and outside temp.sensor have nothing to do with the seatheating as far as I know. The heated seats have a thermostat built in to keep the seats from overheating. They keep the temperature from the seats at skin temp. that's around 25c iirc. If the mats are not repairable you can get generic heating mats at an automotive store to replace the originals. Those get warmer then the originals. Another option for these connectors may be for the SRS belt tensioners. Good luck hunting for the culprit! __________________

Mar 9th, 2010, 08:30	#7
carl4u44 Master Member Last Online: Sep 7th, 2023 17:21 Join Date: Feb 2009 Location: kk	Sorry, the bulb lights and the system works - just never showed as a fault on the diagnostics side. I remember installing those seats a while back, looking at 'the tensioner/seat belt charges'.... no electrical wires were ever plugged into them and even on the removal of my older seats.. Perhaps on the 400 series it was an added luxury upgrade to have the seat belt tensioners! Last edited by carl4u44; Mar 9th, 2010 at 08:35.

Feb 23rd, 2010, 19:41	#3
carl4u44 Master Member Last Online: Sep 7th, 2023 17:21 Join Date: Feb 2009 Location: kk	Many thanks on that b20. I'm actually thinking those brown spade wires may be to do with the heated mirrors on some models. Anyhow I shall get on with checking the 12v current tomorrow in better light. Having read the older posts im wondering if an outside temp sensor or cem might have something to do with it....Or perhaps I may strike lucky with this 'plug and play' option im trying at the moment! As long as im getting power to the seats then I shall take on the 'seat mat challenge'.

Mar 8th, 2010, 10:22	#5
carl4u44 Master Member Last Online: Sep 7th, 2023 17:21 Join Date: Feb 2009 Location: kk	ok well there is power getting to the seats but the seats are not heating. Im guessing im going to need to repair or replace the element inside. As mentioned earlier in the post, the second wire to the drivers seat actually controls the seat belt clicker! The two single brown wires tucked away seem to be for the seatbelt tensoners but im wondering why they never showed up on the srs light to begin with!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)