I have a 2004 Chevy Silverado 2500hd that has some weied electral issues. First the horn stopped working then worked, then the odometer reading stopped working then worked, then the remote would not unlock door’s then worked. Heated seat drivers side worked then don’t. I use the key to unlock door horn alarm goes off. A guy told me to take a blow gun and blow out the steering wheel lots of dust came out horn working then stopped working. Anyone know what it mighty be? Thanjs
As far as the horn goes, I’ll give you some common culprits
The horn contacts
Spin the steering wheel. See if the horn works in certain spots, but not others. If that is the case, the horn contacts are NOT the problem. In that case, the turn signal switch and the turn signal cancel cam are the real problems. The cancel cam has slip rings, and they develop a serious groove over time. The turn signal has a copper “button” which is spring loaded, and becomes weak and worn over time
Since the horn sometimes works, we should assume the relay and the horn itself are okay. Actually, you most likely have 2 horns . . . a low tone and a high tone
Body control module.
All the accessories you mentioned are controlled by it.
Could be as simple as a corroded ground, for the BCM
I’ll second the corroded ground. That can cause a multitude of electrical stupidity.
Take a look under the truck, right about midway from the seat to the firewall on the driver’s side. You may see two black (ground) wires attached to the outside of the frame facing rearward. Clean those 2 grounds or even combine them under a single screw after cleaning. Put a little grease over it after you are finished. That may help, or solve your problem.
Good ideas above. With multiple electrical problems I’m always suspicious of the battery voltage too. If you have the test equipment, maybe give it a look at the time the symptoms are happening. Battery voltage with the engine running should normally be in the 13 to 15.5 volts range. Measure both between the two posts, and beween the battery connectors themselves. There should be little difference b/t those two measurements.