Hey guys,

Thanks for all the responses. Sorry I should have replied to this thread once I figured it out. What it actually was, was that since the truck was used I'm thinking that the previous owner had some aftermarket headlights on the truck and took them with him when he sold the truck. I had a look at both headlight wiring and they were both snipped and then crimped back together, which makes me think they had aftermarket lights in. Anyways, what it was for me was that they wired backwards the high and daylight running wires. So when I was just on daylight, the high beam would be on, but when I put my lights on, the light was on high beam, then on day light running when I would put my high beams on.
All I had to do was switch 2 wires and then things were good!

 

Its all great advice here, I had a similar problem but it was my low beam on the passenger side wouldn't work, I tried all the regular test as I am a mechanic. What I ended up finding was a corrosion build up on the PCM that's attached to the fuse box. Once I cleaned these up everything was fine.

 

The circuit lines on the circuit board in the fuse box are very susceptible to corrosion. I can see the contact points from the silver control module mounted on the side being cause for concern. I had 5 breaks in the tail light circuit from corrosion all within a 3" strip. Two hour repair start to finish. 30 cents worth of solder and wire v.s. $600-$800 for new fuse box courtesy of the dealer.