Car electronics issue. Small but weird

On my 2005 GMC Envoy Denali, have two issues that are impossible to find on the internet. The seat warmer lights - y’know the LEDs that indicate the heater is on - doesn’t come on. But the heater seems to work just fine, it’s just the LEDs that don’t work. Also, you know the annoying buzzer when you open your driver door and leave the key in the ignition? That don’t work either. I don’t know why those two would be related, like I said my google-fu is failing to find anything on either issue. Can they be related? Is it probable they are related? Where should I start looking assuming all of the fuses are fine?

Are all the fuses fine?

I am checking them out tonight.

I can’t imagine what else it could be. LEDs can “burn out”; they’re at least 16 years old at this point.

As for the door chime, that is usually output by the door speakers. Do all of your speakers work?

Alternatively, there’s usually some very convoluted procedure to toggle that sort of thing, like “open and close the rear passenger side door twice, turn the radio on and off 4 times, flip down the driver’s side visor, then do the hokey-pokey.” Is it possible you unknowingly did all of that at some point?

There are electronic setting through the steering wheel (Denali package). I’ve checked them all but if the fuses don’t fix it then I go through all the settings again.

It’s possible they’re not actually LEDs and they’ve just burned out. I had a 2002 VW Passat and the backlights for the dashboard climate vent wheels had what was more like a small Christmas tree light bulb behind them. If they are LEDs then the electronics can still fail. Fixing it would likely entail either replacing the whole switch, or doing some soldering.

One possibility could be cold solder joints in the dash control module. Not too hard to identify once you get the module out.

Definitely check the fusebox – I’ve had multiple problems with cars be fixed by replacing a ~50 cent fuse.

I drove a GMC Sierra from about the same year and it had dedicated box under the dash that made the noise. I pulled it out because I was doing a lot of work on the car and got sick of listening to the noise. Granted, it’s a lot easier to find it when it’s making noise.

If the seat heat settings are on the steering wheel, that could lend itself to both of the problems being related. Only because the wires that tell the car the keys are in the ignition and the wires that go to the steering wheel will travel though the same, small, cramped steering column. But I’d think if this was related to the ignition cylinder, you’d have noticed other problems and things up on the wheel often take out more than just a few lights on one button. Plus, anything on the wheel has to deal with the clockspring which adds a bunch more complexity that something on the ignition doesn’t have to deal with.

Better question. Does the dome light come on when you open the door? If it doesn’t, it’s more likely the door open sensor that’s causing the problem.

Ohhhh Good point. I’ll check that out.