[TXExpat]

So when i was aligning the headlights on my 1997 C1500 last night I discovered a new issue. The DRLs and headlights are the same level of brightness. I can't say for certain but I'm guessing that the headlights are the DRL brightness. They don't look all that bright but I guess it could be the other way around; I'm not certain how to even check which light output is correct.

Anyone have any idea where I should even start looking for the problem? I just replaced both headlight housings because the original ones were weathered and didn't allow the headlights to throw much light. Obviously I think this issue may have made it even worse, but I'm fairly certain that this problem existed before I switched housings. The headlight switch itself is working properly, it will turn on the marker lights in the middle position and brings the sidelights on when put into headlight position.

 

[Ethan]

Did you put 4 of the same bulbs in? The outside bulbs are your low beam, and the inside bulbs are your high beam, so it's two different bulbs in each housing.

 

[TXExpat]

Nope, it has two different bulbs.

 

[TELORVEHC]

How old are your bulbs? Also, make sure your headlight wires are making good connection and aren't loose, damaged or frayed.

 

[stephan]

I'm guessing that the HLs are down to the brightness level of the DRLs rather than the DRLs being too bright. This could be a loose or bad ground connection (HL circuit) cuz it will cause high resistance & cause the lights to be dim.

 

[TXExpat]

Hmmm. Ok. I'll see if I can do some investigation on the HL circuit grounding and see if I turn anything up. I'm also going to see if I can disable the DRL module and see if that makes any difference. The bulbs are all new and I did give the connectors and wires a once over before I buttoned everything back up.

 

[Revredneck]

If you set the parking brake with the ignition on, it should turn of the DRL's. That's a quick test of the system. There is a relay in the underhood fuse and relay box that can cause problems with the headlamps. I agree with those who say you should also check for a good ground for your headlamps. Sorry, I don't know the exact location of that ground, but you should check on the radiator support and be sure the battery to body ground is good.
Good Luck and God Bless

 

[TXExpat]

I was out of town for a while so I didn't have time to mess with the lights but I do know the DRLs do shut off when the e-brake is engaged. I'll see if I can track down the ground location this weekend and see if that provides any clues.

Thanks for all the advice, I appreciate it!