Vannin' Community and Forums Forums Chevy General Discussion Headlights dim when on the gas pedal.

When I let up off the gas pedal, the headlights brighten up, but when holding the gas pedal, even on level ground, the headlights dim.

Sounds like an issue with the alternator or a bad ground.

Belts do not always squeal when they slip.

I've witnessed this with an optical tachometer on a boat. a 2 to 1 pulley ratio was reading as if it were a 1.5 to 1 at 1200 rpm but was 2:1 at idle

A slipping belt would most easily explain this symptom, but do always find and clean the grounds wherever you find them

I agree with Rusty. I bet it's a ground. All good advice though.