[Big Cheese]

The other day I noticed a flicker in my low beams about 30seconds after i turned them on, but never again throughout the trip.

Tonight tho, when I turned them on, they went out, and won't work. The highbeams work fine. Are there separate relays for the high and low beams, and where are they, behind the kick panel in the cab?

 

[skelley521]

Both the right & left flickered and now both are out?
1st you could check the fuse panel under the hood.
Looks like #1 & #6 for low beams for 06'-'08
Pics to follow...
Both going at the same time sounds odd if that is the case.
I'd be checking battery date/conditions/connections and put a eyeball on the ground to see if has a good connections.
Also you would get more help if this post was in the right section, maybe a mod could move
Best of luck....
Edit: Are the bulbs good?

 

[Elkhunter]

Any other mods done? Something that might lead to a corroded ground wire?

 

[Carsmak]

I'd definitely, check light bulbs, grounds, and the age and condition of the battery. But before you do any of that, try tapping on the headlight switch itself. Mine is failing and at times it will turn on right after start up. The part is about $50, so I'm hoping it's not that for you.

As for the Headlight Bulbs, I recently read a post where someone was commenting that there '06 only recently needed new bulbs, (like this summer), If your '08 is still on originals, I'd go for replacing them first. Then, if your not sure when the battery was last replaced I'd put it on the short list of items which may need replacement. While checking out the battery, you can visually locate the grounds in the engine compartment.