Hello Everyone,

About a month ago I noticed that my 04 Limited's driver seat heater dial/switch light had a faint glow to it when it was turned off. A few miles down the road my seat was warmer than it's ever been (still in the off position). I popped the center console cover up and unplugged the heater switch but this did not solve the issue. Since it's winter here I figured I'd wait till spring to fix it...... Until yesterday. The seat is now emitting an electrical burning smell that made the interior of the vehicle unbearable. I believe I've found the fuse in the engine bay and will remove it today. But, it's 0 degrees here and would like some input on the situation.

Has anyone else experienced this? Simple fix or P.I.A. ?

Thanks in advance!
-Eric

Some fuses in these trucks cover more than just what is listed on the fuse diagram I'd unplug the connector from the bottom of the seat. Your 04 shouldn't have side airbags in the seat so I think you'd be ok to just unplug things till you find the one that kills the seat. Just don't unplug a yellow connector or a connecter with wiring having yellow loom on it

Thanks for the recommendation. What does yellow represent? Airbag?

Yes, I believe yellow wiring is typically air bags, especially under the seat.

If yours has side airbags you'll have a RCSA Off button to the left of your steering wheel in the little button cluster. You'll also have "SRS Side Airbag" tags on the front seats and markings on the A and C pillars indicating "SRS"

Should have 25a "SEAT HEATER " fuse.. remove that.
Anything under seat?

It's been 0 degrees and windy the past few days.... I'll get a better look under the seat this weekend.

What's confusing is the fact that even with the control switch removed the seat is still powered. I'm guessing that the seat heater is powered similarly to a car audio amplifier, where the control switch is only a remote power switch with the main power supply being fed directly to the heater.

Can anyone confirm this?

Thanks again for the input guys.

Not sure if the seat heater has a relay or not, I would think it does, but the switch could control the relay and the relay sends power to the heater coil when the switch tells it too, if the relay is bad/stuck it could be sending power to the seat heater even after removing the switch.

Just a thought, maybe someone knows if there is a relay or not.

If anyone still has this issue, I fixed it on mine.

Under the seat, there is a small black box component under the seat that was getting incredibly hot. It was two plugs and two snaps to remove it and upon further inspection, the internals were fried. The Toyota part no. on the component is 87501-60050 and upon further research with Toyota, 87501-60040 replaces this piece. Here is a link for the piece:

https://parts.toyotaoftampabay.com/o...rol-8750160040

I have one on order and am going to replace the switch (84751-35110) as well in case it was sending a bad signal to make the controller overheat. Hope this helps any one else!