I have a 2000 c/k series 3500 truck I bought new. Great truck. I'm having a problem with the turn signal, dash lights. When headlights are not on and I step on the brakes, the dash lights illuminate. When the headlights are on, the left turn signal does not blink, only buzzes. Anyone have an idea? Thanks

 

I'm not familiar with your specific truck, but this should apply to any vehicle. Make sure all your tail light bulbs are properly grounded. You can also ground them temporarily with a test lead to see if this fixes the problem.

 

Problem solved. $9.99 The left rear stop/turn/light failed internally. This caused my dash lights (daytime), fuel guage, brake signal, turn indicator (left. at night) to go haywire. The left turn light and signal beep worked fine in daylight mode. It finally stopped blinking "left" in daytime mode (fast flashing), so I changed the assembly. Cheap fix for five problems. I have a service body with aftermarket light assemblies. Love my Chevy!

 

Thx for posting that solution! I know in the future others will find less headache in their problems while reading these forums.