I just bought a 97 gmc sierra and I noticed there is no difference between the daytime running lights and the low beam lights. Is this normal? I'm asking because a) I have no clue here and b) the low beam lights are really dim.

 

Could it possibly be the plastic lens are old?

 

My 98, with the "quad" headlights does not behave the way you describe. When the engine is running and the emergency brake is released, the two low beams (outside) go on. When I turn on the headlights, they get brighter.

 

Cowboy, That is what I thought. The daytime running lights were dimmer than the low beam lights. But on my truck there is no difference.

I'm pretty sure the plastic lenses are cloudy and should be polished or replaced, but that does not seem to be the main problem here.

 

I wonder if there is a relay in the circuit that puts a resistor in series with the lights to make them dimmer when they are acting as running lights?