This is not about DRLs. DRLs only come on when you take the transmission out of park. This is about automatic headlights (and dash lights) that come on when you turn on the key when it's dark and sometimes even when it's not. It makes them come on and go off with the headlight switch. If you can't (or don't like to) operate a light switch don't do this.
Tested on a 2005 Tahoe LT.
Find BCM C3 (brown) connector white wire (position A4 on connector). Cut white wire about 4" back from connector. The harness end of the wire is no longer used and can be taped to the harness. The connector end of the wire gets connected to one end of a .5 watt 1.8K Ohm resistor.
Find the BCM C4 (light blue) connector black wire (position B7). Cut black wire about 4" back from the connector and tee in a new wire. Connect the other end of the new wire to the resistor. Tape the wires as you make each connection then tape the whole thing to the harness.
If you loose a connection what will happen is your lights will be on whenever the key is on.

 

I can't help you. I DO like the automatic lights. When I was driving truck, I always had my headlights on. I'm, getting so use to it on my 15 Malibu, I forget the lights on my 1998 Chevrolet K-1500 doesn't have automatic lights, though it does have automatic DSL lights. I can't believe the idiots that don't turn on their headlights in inclement weather or near dusk. Whatta bunch of fools! Save a battery, but end up in an accident? Not me.

 

I agree on when to drive with your lights on. I just don't like them on when as soon as I turn the key on. I like to let the engine run for a bit and recharge the battery after starting. Also if I turn the key on to roll up a window or check something out I don't want them on. A lot of it is just what you're used to. If you hadn't gotten used to automatic lights you would always turn them on yourself. Thanks for the reply.