I have a 2000 Chevy Tahoe Z-71 with 55,000 km on it. It is the older generation style for that year. The DRL's or daytime running lights stopped working before the extended warranty ran out in Oct. 2007. The GM garage replaced the module and a diode. However, during a recent trip to Montana I discovered that the DRL's are BRIGHTER than when I turn on the low beam headlights. (The speed limit is 75 mph in Montana on the Interstate so I did notice that I could see better with my DRL's on than with my headlights turned on.) Why would any GM engineer design a vehicle like that? The service department said that everything was normal. I asked why the DRL's were brighter. They said that when the headlights are turned on, there is more current draw and the lights are dimmer. Well, with the DRL's on AND the fog lights turned on, the DRL's are still way brighter than with the low beam headlights on. So I ended up driving down the Interstate with my parking lights turned on, the DRL's on, and the fog lights on as well just so I could have brighter lights for driving. By the way, the little green headlight on the dash was on as well. The operating manual that came with the Tahoe says, "The green light on the dash is to remind you to turn on the headlights when it is dark". I wonder why you need the headlights when the DRL's are brighter anyway. Why would they want you to turn on the headlights so you can have dimmer lights! I would appreciate why I am having this lighting problem. Then again, it just might explain why GM is having some trouble staying “afloat” right now. What kind of engineer designed a system that does not make much sense at all! I would appreciate some help. The vehicle is at the GM garage now.

this is all screwed up this is not the correct operation ...as you well know these dealer tech's aren't too bright electrically...

the dealership should fix this probably the bcm...

Sounds like there is a current drop thru the headlight system. The components for powering the low beams (when the headlites are turned on) are these:

1. Lighting fuse #8 50 Amp (underhood fuse block)
2. Headlamp switch.
3. Headlamp dimmer switch.
4. DRL relay.
5. Wiring and connections.

Start with changing the fuse even though it looks good and go from there.

Also I don't think your 2000 (old body style) has a BCM (Body Control Module) to worry about.

Sounds like there is a current drop thru the headlight system. The components for powering the low beams (when the headlites are turned on) are these:

1. Lighting fuse #8 50 Amp (underhood fuse block)
2. Headlamp switch.
3. Headlamp dimmer switch.
4. DRL relay.
5. Wiring and connections.

Start with changing the fuse even though it looks good and go from there.

Also I don't think your 2000 (old body style) has a BCM (Body Control Module) to worry about.

sir I suggest you check your sources ...the BCM is installed in this vehicle...

Curious as to what exactly was replaced as I have a 1999 version of your vehicle that the DRL's are out on and it is way outta warranty and I just haven't worried about it after not finding any blown fuses.
Thanks in advance...............

Curious as to what exactly was replaced as I have a 1999 version of your vehicle that the DRL's are out on and it is way outta warranty and I just haven't worried about it after not finding any blown fuses.
Thanks in advance...............

check the IGNE,DLR fuses. 10amps,,..replace the DRL relay...If this does not work out ,, the BCM grounds out the DRL relay coil , so as to energize it...if the relay is not energized, then your BCM or wiring/connector to unit is n/g...this wire is light green/ black...
happy hunting..

I can't locate the DRL Relay on my z71 or the bcm if it has one. I have the same problem with the daytime running lights, and the fog lamps don't work anymore. I would replace the relay if I could find it. Anyone have a detailed description of the location?:confused: