Seat Heaters Revealed

[mts]

Originally posted by "TrueNorthMilly"

 

Hello my Millenia friends. Many of us northern members suffer with cold bums in the winter because our seat heaters are broken. Toast, like in cold toast.

 

I, being a person of determination, decided to do whatever it was going to take to fix the problem. As an engineer, I approached this in a systematic way. I first obtained the wiring diagrams and located all the possible failed components.

 

You have to first start with the two fuses that might be blown.

 

Next you check the relay behind the rear seat to see if it is powered and delivering twelve volts to the switches.

 

Next you have to check the switches to see if they are in fact powered, ready and able to deliver power to the seat heaters. In my case the little lights did not illuminate so I replaced the switches. Getting them took a week. Don't try and pry them out, you have to start inside the center console and remove the panels around them.

 

Each seat is a circuit on its own. There is a heating pad inside the seat bottom, and another in the seat back. If either of them is burned out, the seat will not heat. It is possible for one seat to be burned out and not working, while the other one works fine. They are very separate, at least after the relay.

 

After I determined that power was being delivered correctly to both seats, and still no heat, I decided to really get into this. This forum contains some real myths about the seat heaters - let me clear these up. You do not have to take apart any of the leather. Once removed, the seats come apart fairly easily from the bottom. You have to remove the hog-rings that hold the main seat cushion in place. This takes hog-ring pliers and some strength. Once you release the hog rings, and are able to lift the seat cushions, you will be able to remove the seat heaters.

 

Here's what they look like when they are out:

 

 

Here's some close-ups of the burned wires sticking out.

 

 

 

It is my opinion that the chance of failure of the fuses, relay and switches are pretty remote. The failures are ninety percent the seat bottom heating element. Failure of the element in the seat back is not very common, and in my case I didn't try and remove them because they worked fine.

 

Once you have the element replaced, you have to use those hog-ring pliers and some new hog rings to put everything back together.

 

The replacement heating elements are not made by the same company as the originals - probably a good thing. Maybe the replacement parts will be better than the original ones.