you can also have a wire that is exposed and that can be making them to flicker
The alternator is on the way out.
Probably your alternator.
The headlights may flicker.
voltage regulater on the alternater is going bad
When a cars headlights, AC, and radio are losing power, it is possible the alternator.
You may have a pull on your batt, or a surge.
I had this problem and it was a bad alternator.
Sounds like you need a new battery.
If the lights flicker when the vehicle is running, the alternator is on it's way out.
you probly just have a bad conettion just take it to your local shope it shouldn't be over 50 dollars to fix.
Flickering headlights on a 2005 Silverado may be caused by faulty relays or electrical wiring. The fuses and lights may also be going out.
Sometimes the ground strap to the body of the car can come loose. This will cause things to flicker. Ground from the battery needs to be connected to the engine block, the frame, and the body to keep things working properly.