Well, just about done putting my interior back together, was testing the passenger side power seat switch, when suddenly both power seat controls stopped working, and got a faint whiff of that awful electrical burning smell, so I quickly disconnected the battery.

After some checking, the WDO circuit breaker in the fuse box was too hot to even touch -- I waited a good half hour or so for everything to cool down, swapped out the circuit breaker with another one, and...still no power seats, and the "replacement" circuit breaker again got very very hot.

I have the battery unhooked now for safety, question is what could have gone wrong? I did notice the diode on the bottom of the power seat switch control appeared to be toasted when I was putting it back together, but to my understanding the diode is not essential for the operation of the seats...???

Any ideas/comments/suggestions greatly appreciated, thanks again! I have the standard seats not the sports seats BTW

Joe
1991 L98 auto

I don't know much about these, but did you pinch a wire when you bolted the seats down?

Matthew

Does the drivers seat work okay with a new fuse?

It surprises me the seat can overdraw the circuit like that. This stuff usually uses current limiting switches to kill the motor during normal use when it reaches the end of its travel.

I'd pull the passenger seat out and see if the motor is getting power there. Otherwise may be a short at the switch itself. Anything you messed with is a more likely culprit of course.

Well, I am pretty sure I found the problem -- disconnected the power connector to the window switch in the console; now how to fix it?

In the power connector for the power seat switch on the console (standard seats not sport and no FX3) there *was* (key word) a diode across 2 terminals -- the diode is no longer there, from either an overheat situation or a short to the (always) hot orange wire.

I can patch up the wiring easy enough, the question is, do I really need to replace the diode? What does it do, exactly, and what are the specs for it? (can't find them in the FSM).

Lastly, if I can leave it out should I snip off the bare wire ends of what is left of the diode or are they harmless?

Appreciate the help all, thanks!

Joe

1991 L98 auto

We'd need to see the Helm manual.

You sure it's a diode? I only ask because you called the fuse a circuit-breaker.

It is a diode according to the FSM -- and it's not a fuse it is a 30A circuit breaker, just not the WDO one, it's the Power Accessory circuit breaker...checked the electrical FSM and that's what it says..."diode taped in harness" (well not anymore LOL) thanks.

Diodes are used to isolate circuits and prevent power from flowing backwards into other circuits.

I'm not sure why it would melt, but if it's there, it probably can't work without it.