Any Chevy mechanics on here? Strange issue..

[cornfedkiller]

2014 Silverado 5.3. High beams will not shut off. When I toggle the lever on the column, nothing happens, high beams stay on. When I turn the truck off, the upper (low beam/daytime driving) lights stay on for like 30 seconds or whatever and then they turn off, but the lower lights stay on. Only way I can get them to turn off is pulling the fuse in the panel under the hood. I tried disconnecting the battery for 30+ mins (two different times) and when I hooked it back up, the lights were back on.

Had this problem before but it just went away on its own after a couple hours.

Maybe a relay that’s stuck on? There are no headlight relays in that fuse panel, so I’m not sure where it would be or how to test it?

 

[TaperPin]

This may not be the diagram for your truck, but it might be. I’m not a Chevy guy, but I watch South Main Auto on YouTube, and know just enough to be dangerous, so this might be incorrect.

The dimmer switch pulls the control wire to ground that goes into the body control module. If that wire is pulled to ground all the time it seems like it would be your switch is bad, or the wire is grounded out somehow.

If the switch wire is ok and not grounded out, then the signal wire to the headlamp relay from the body control module may be on all the time (malfunctioning body control module or wire shorted to power), or the relay is bad.

A scanner that reads live data could tell you if the dimmer switch was functioning and commanding the body control module correctly. You could probe the signal wire for the relay for voltage, if there is none, then it seems like it would be the relay is bad.