I have the same problem on my Tahoe and I was told that if the green indicator light is on and all the fuses are good that it is either the module or the diode. I'm not sure where the module is but the diode I found under the dash. It looks like a small finned heatsink.
No.
headlights
NO , Not from the factory.
Yes
The daytime running lights are connected to the bright lights. It just reduces the power for the daytime runners.
www.fixitnow.com
They are daytime running lights. They are always on so people can always see you. Its a safety thing. Newer trucks have specific daytime running lights.
yes
DRL = daytime running lights
yes , by removing DRL
When daytime running lights do not work, it means the bulbs may have burned out. It could also mean the fuses have failed or there is a short in the wiring.
Lift up on the E-brake until the first click. This works for any vehicle (Chevy at least) with daytime running lights.