Where is the fuse located for the daytime running lights on a 2005 Chev Siveraado?

It is located in the underhood fuse/relay box , marked DRL 10 amp fuse ! Also if that is good check the DRL relay in the same fuse/relay box .Your light sensor could also be bad .
The daytime running lamps (DRL) will operate when the ignition switch is in the RUN position, for automatic transmissions (A/T), the gear selector is not in the PARK position, the headlamp switch is in the AUTO position, and for manual transmissions (M/T), the park brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate. The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal it will either turn on the DRL or the headlamps for auto headlamp operation. Any function or condition that turns on the headlights will cancel the daytime running lamps operation. The DRL can be manually turned OFF by depressing the AHL/DRL switch in the headlamp switch
Do you know that on inside of fuse box lid it shows what fuse is what .