Daytime Running Lamps

[drwet]

I have a 2003 ZR2 which I have only owned for the last couple of years. The headlights are always on. On everyonther GM vehicle I have ever owned, the headlights go out at some time. On my Silverado they go out if you step on the emergency brake. On the ZR2 they are on at all times. According to the service manual the ZR2 has different headlight wiring from the other trucks. (No DRL ground relay.) Does anyone have a similar truck, and can tell me how the headlights are supposed to work? I can't believe they are meant to be on at all times. If that's the case, why is there a headlight switch?

 

[lmleck]

If they go off when you click on your turn signal, they are the drl.
If not, they are on because of the daylight sensor on top of the dash, right side speaker grill.
The sensor circuit could be bad or weak if they stay on, mine occasionally will turn off during the day.
I have 2003 sonoma.

 

[drwet]

Thanks for the reply. What I need to know first is how are they supposed to work? Should they go out in park? What about when you apply the emergency brake? Do you have a ZR2? And, if you can stand one more question - why would the daylight sensor have anything to do with it?

 

[lmleck]

My drl are disabled by a relay pin being bent out of the socket. That cured them being turned off when the signal light was in use. (A quirk installed at the factory with a computer program in the bcm.) GM thought the signals on a gmc sonoma would not be seen easily as they were immediately beneath the headlights.
My headlights come on with the key and stay on until the sensor is in bright enough light for them to go off, or I disable them with the dome light button by pushing it 2 times and releasing it.
That is all.

 

[fishin_wi]

lights

I have a 2000 gmc and i can turn them off by depressing the dome light button 2 times. otherwise they should go out if you put the park brake on, if its light enough outside. also i put it in park during the day and they go off. I'm not sure which year they changed it, but I tried it on a 2004 silverado, and they dont shut off ever. good luck