brake,tail and dash lights not working

[jibberlo]

I have a 74 3500 dually, I put new bulbs in the roof running lights and everything worked fine for about 20 minutes then the dash, brake and tail lights stopped working. I checked all the bulbs and their good and I replaced the fuse which blew. Right now I have only headlights, reverse and turn signals working. I know it's probably a ground wire but I was under the truck and didn't see a ground for the rear wiring. Is the rear lights ground in front of the rearend or shouldn't it be right at the cover over between the tail lights?

[Irish_Alley]

If you blew the fuse it’s probably not a ground but a grounded power wire. Did the new fuse blow yet? Did they work right when you replaced the fuse?

[jibberlo]

The new fuse hasn't blown yet, and the lights haven't worked since it blew. Only half of my roof lights worked even after I replaced the bulbs. I moved the two around that didn't work and they cam on. I then went to replace the side lights in the wheel tubs and when I put a bulb in on tub it worked but thats when all my lights went out. I been trying to trace the side marker wires into the harness to see if I can find a ground that has came loose but no luck so far.

[DnStClr]

jibberlo, there's a wiring schematic in the technical section of this web site. It can help you in your troubleshooting.

[Irish_Alley]

A ground wouldn't blow the fuse Juarez cause other problems like if you turn the turn signal on it will blink the head lights or something else.

[txchainsawgogi]

Sounds like an exposed power wire touched metal, blew the fuse, and maybe its not touching anymore? Look for wires that have room to move around...

[jibberlo]

I rewired a ground on the rear, who ever did the wiring put all the grounds to one 18 gauge ground. I found one wire on the roof lights that was cut open about 1/2 to 3/4 inch where the power wire was touching the frame. I ran a new power wire up to it, but there still has to be a power wire touching somewhere that I haven't found yet. I also found that the neutral safety switch is bad because the truck wont start in neutral.

[txchainsawgogi]

I'm in the same boat. I swear a monkey with a brain tumor could have done a better job wiring my truck than the previous owner.

[billwater24]

I have found ground issues and bad connections are the whole key.  However I had a bad fuse, not blown, but not conducting.  A good ohm meter and a test light will narrow it down!

[bake74]

     I'm with Irish on this one, fuses are blown from power wires touching a ground where they are not suppose to, if it was a actual ground wire not hooked up or broken, then none of the lights in that circuit would work.  Or in my case where the rear lights just stopped working all of a sudden, was due to my bed ground wire breaking leaving a open circuit.