heated seat query

[Bandit12]

Hi all,
I've an x7 with heated seats. Problem is the missus often forgets to turn hers off and as I also do quite alot of solo driving i dont want the heating elements to burn out. Solution is to fit some kind of warning light onto the dash as a visual clue that they are on. the switch has 3 wires (grey, yellow and green) I thought i could simply splice wires into the power and earth and run them via the central tunnel under the gear selector to an led mounted on the dash.

I believe grey is main power
yellow is switched power to the heated elements
green is the earth.

Problem is I put a multi meter across the 3 wires to see the voltage to select appropriate LED and got readings of about 0.5 volts from the grey to green. This makes no sense to me as i was expecting about 5 volts required to operate the solonoid for the heating elements.

Question is this, has anyone already tried this? I'm sure its a simple task but i would appreciate if someone can confirm which wires are doing what job and the voltage they are carrying.

Any help /advice is most appreciated

Bandit

[admiral51]

I could well be wrong but i think there is some kind of "pressure pad" built in the system which will be a safety part of the design.
I have left my C4 heated passenger seat set to high and it never seems to warm up unless someone is sat in it.

Colin

[GiveMeABreak]

I don't think burning out is the issue when they fail - it's more likely down to physical wear with all the sitting and lifting on the pads.

The 3 wires you mention are only for the rheostat controls which go to the seat control units in the seats.

[wheeler]

Agreed that they normally fail due to flexing rather than anything else.
I also find heated seats dont work that great unless you are sitting on them but always just assumed it just ‘looses’ the heat easily unless your body is there to kind of keep the heat in. I find if you run the car for 15 minutes to defrost on the driveway with the heated seats on full when you get in the car they dont feel like they have even been on till you sit for a few minutes.
As for fitting a tell tale I suppose you would need to connect directly to the wires the elements connect to.

[Bandit12]

Thanks guys,
I had also noticed that seats don't appear to start warming until you sit on them but didnt think much of it. Easiest option i think is to remove a seat, turn it upside down and have a proper look at the wiring. Not the simple task I originally thought so I'll save it for another day.
Bandit

[GiveMeABreak]

Be aware that if you have leather seats the leather is bonded in most places. The heating pads are not sold separately, only as part of the backrest or seat cushions.