I tried a different switch and still blows the fuse, here is what I've got so far if I unplug the dimmer in headlight switch it won't blow, also if I unplug the smaller plug from the multifunction switch the one to the left it won't blow and my instrument lights do work but I have no headlights, that tells me there is something going on with the ground in the cluster or the trailer wiring which I haven't looked at yet. Any more suggestions??

 

Looks like there is a lot of stuff powered off of that fuse 18. Looking at the diagram below, are there any other symptoms that may be relevant? Did your overhead console stop working? Cruise control? Horn? Ashtray light?

Maybe try snipping that brown feed to trailer illumination?

 

My over console works, cruise control and horn don't work and no ashtray light either. I must mention the truck was involved in a front end collision if that helps.

 

I would first check that the ashtray light power supply isn't shorted to ground. Since you mentioned a collision, I would look over all the front lighting wiring and see if there are any frayed or broken wires or sockets.

The cruise control and horn both rely on the "airbag sliding contact" and the cruise control module, so I would investigate the wiring to that as well. Maybe try unplugging the cruise control module and see if the fuse survives.

 

NOW you tell us - it could be just about anything under there. All it takes is one pinched wire somewhere.

 

There U have it if U popped UR airbags. Look at Collum first and then keep on eliminating circuits. U can use a fuse circuit tester to cut down on the number of blown fuses while looking. Maybe power to the doors got wire damaged. Heck it is probably UR clock spring. Wires got mashed together knocking out those items.