Hi

I am trying to fix heated seats on GL450. Whenever I press on the heated seat switch, it flashes for about 2 seconds and goes off, and no heating happens on both driver and passenger seats. I have read that the most common cause of this problem is discontinuity in the heater elements and I was getting ready to tear the seat apart to find the break in the circuitry. However, when I took out the seat, the seat circuit seems intact when I tested with a multi-meter. I went back to the car and tested the continuity of the circuit before the seat and there seems to be a break. I have looked at circuit wiring diagrams and there seems to be a relay, which I cannot locate in the car.

My questions are: 1. Where is the heated switch relay and I how do I test it? 2. Where else do I need to look to find a break in the circuit?

Thanks

 

There is a class action lawsuit going on if yours is an 07

 

Thanks,

I am aware of the class action suit and I think it is about a separate issue on seats smoking and burning from malfunctioning seat heaters. I am hoping to restore heat to my seats by fixing the break in the circuit, which by my testing, is located between the power supply and the seats and not in the seats. Could anyone else have tried fixing this problem?

In the attached wiring diagram, the break in the circuit is likely to be at relays K/59 or K/59/1. I cannot figure out where these relays are located in the car.

 

Rear of car passenger side

 

Thank you so much

I opened the cargo compartment fuse box and found that the slot for K relay is empty. This is odd. Does K relay do other things in the car, apart from heated seats? Nothing else does not work in the car, apart from heated seats. Why would anyone remove a relay and not replace it? How would I know which relay to buy to replace the missing one?

 

Buy from dealer like15 bucks

 

Thanks

Will do that and see what happens

 

I just bought a relay and inserted it into slot K on the cargo area fuse box. Nothing happens. My heated seats still do not work. It appears relay K is redundant since relay R on the same fuse box does the same job of completing 15R circuit, which is required for heated seats.
Now I am stuck. Does anyone have any idea what else I need to check?

Thanks

 

Have you checked all your fuses

 

All of them; I checked all fuses in the 3 fuse boxes(Cargo, Cockpit and Engine compartments) and each produced a 'beeping' sound on continuity testing. The thing that puzzles me is where F1/f6 fuse, which is included in the wiring diagram, is located. When I checked the description on location of fuses, fuse 6 is located in the prefuse box in the battery compartment. It also checks out fine. But F1 refers to the cargo compartment fuse box, which only has fuses numbered from 10 to 72. I also think that since I checked all fuses, it shouldn't matter where F1/f6 is located.

Are there any other components that are involved in heated seats circuitry? I read somewhere that the heated seat module is 'common' and other functions would fail, apart from heated seats, if this module were to fail. This rules out any module problems since everything else is working fine in the car.

 

Star diag is next... Usually a falty element

 

Is it possible to have a faulty element and still have a complete seat circuit? I checked the circuit on the seat at the seat plug and it seemed complete. However, the circuit before the seat plug is incomplete (with ignition on- circuit 15R and switch pressed on). This is why I thought the problem could be elsewhere rather than the heat elements.
I will continue researching it.