both tail and license lights went out

They were all working yesterday and I just got pulled over twice on my way home. Thankfully, no tickets. Since I'm dealing with multiple lights I'm thinking its not bulbs and probably wiring - a bad ground or something of the sort.

I'm confident I can figure it out but any tips on where I should look first? Anybody have a wiring diagram that might help? Are those on the same fuse? (Seems unlikely) Wiring is kind of new territory for me.

 

Check the "TAIL" fuse, a 10A

 

Will do now that its light out but wouldn't that take out the brake lights as well? Brake lights work. Running lights and plate lights are out.

 

Check your owner's manual for the fuse box diagram, they might be separate fuses. I agree that it's not a bulb problem, start simple and check the fuses.

 

This happened to me in my 97 a few years ago. I had a trailer hitch, and the wires in the harness shorted out and blew the fuse. If you find a blown fuse and replace it, it might just blow again and you will need to replace the wiring harness for the trailer lights.

 

check the tail fuse like said above. My old truck did that.

 

Tail fuse is fine as suspected. Turn signals, reverse lights and brake lights all work so there's current getting to each bulb except the license plate lights. I looked at the frame wire and associated connectors just above the rear wheel. Everything looks fine. hangers are intact, wires are still in the protective sleeve. I don't have a trailer light wiring harness so certainly no short there! I had a new frame put in a couple years back so there's no rust or other issues under there and all contact points are new anyway. I'm totally perplexed.

 

Oh yeah. I forgot to mention I did find the wiring diagrams and such in the DIY section. Very helpful in showing me where to look but I still can't seem to solve the problem.

 

A bad tail relay?

 

Do you have a test light so you can see if there's current getting to certain points along the circuit? Did you try swapping out the fuse for another of the same amperage, sometimes they look fine visually, I've been fooled by that a couple times. Plus it's a simple check before you start tearing into the truck. If all fuses and grounds are ok, then move on down the wiring diagram to relays and switches. A volt meter or a test light will come in handy if you can get your hands on one.