Keep blowing fuses...getting angry!!!!!

[5150]

Hey guys,

Trying to hook up my new tail lights and I keep blowing the tail light fuse.
It takes it a second and then it just pops. I just cut the old tail lights off and it had two wires. All I've done is try to wire up those two wires to my new wires. I got my volt tester and only one of the two wires lights up so I'm assuming that's the positive.

Need a little help.

Bryan

[ante_up13]

Check your grounds where the housing is bolted to the truck. A little sandpaper on the contacts will clean it up. Also check your wires and make sure they aren't grounding out somewhere. I rewired my whole truck and still ran into problems until the guys on the board told me to check the grounds and everything works perfectly now.

[Longhorn Man]

Your 2 wires, one is tail light, and the other is brake/turn signal. The brown is the tail lights, and then the yellow/green (depending on what side you are looking at) will be the turn/brake.
Does the lamp have 2 wires... or 3 on it? you may be hooking something up to a ground on the lamp assembly if it is a 3 wire set up.
Do the lights light up at all when you tunr them on? If so, what do they look like? one bright one dim? both dim....ect.
Just to rule out any variables, install a new fuse, then unplug the tail light harness under the rear bumper... or at the firewall just to the drivers side of center on the firewall...about where your valve cover is. Then turn on your lights. If you pop the fuse, then you have an issue in the cab and not in the tail lights.

[Stocker]

Originally Posted by yellow69

Trying to hook up my new tail lights and I keep blowing the tail light fuse. It takes it a second and then it just pops. I just cut the old tail lights off and it had two wires. All I've done is try to wire up those two wires to my new wires. I got my volt tester and only one of the two wires lights up so I'm assuming that's the positive.

Assuming you have combo stop/tail lamps, with dual filament bulbs. The base of the socket is the ground. One wire will be hot (positive) for the taillights, the other wire will be hot for brake lights.

Sounds like your new lamps have an internal short, or the bulb itself may be shorted out. Try just one light at a time, maybe also unplug the bulb, then plug in one at a time. To save fuses, while you are trying things, rig up a test light across the fuse position. If it lights up full bright, you still have a short. If it lights up dimly and also lights up your taillight (dimly), then all is good.

HTH

[5150]

My tail lights just have two wires 1 black and 1 white. Someone spliced up the other lights that were on the truck so the color thing doesn't help. I've put different bulbs in and it doesn't help.

One more thing that might help. When I put my gauge cluster in the other day I can't get my instrument panel to light up or my sidemarker bulbs.

Bryan

[Longhorn Man]

Will they light up if you unplug the harness?

[5150]

That's one of the problems there is no harness, but I don't believe they will. They did at first and now I don't think they do.

[Stocker]

Originally Posted by yellow69

My tail lights just have two wires 1 black and 1 white.

Again, we'll assume your lamp has both taillight and stop/turn light. Then you have a mechanical ground at the mounting screwhole. One wire is for tail light, the other is for stop/turn.

With the lamp removed, connect the grounding tab (plate, ring, whatever) to a good known metallic ground, or to the negative battery terminal. Then run a length of wire (fused, if you wish) to one of the lamp wires from the positive battery terminal. You should have light. Now move the length of wire from that lamp wire to the other lamp wire. You should again have light, this time from the other filament.

This will prove your lamp assembly (and bulb) is good. If so, we'll need to work on your truck's wiring.

[Palf70Step]

Other than what was mentione above about knowing the new lights wiring scheme, I'd look closely for a wire that got pinched in the cab or along the bed area during reassembly.

[5150]

Thanks Bill I'll check that. I'm also trying to figure out why I don't have any instrument panel lights, wipers, and sidemarker lights.

[mrein3]

Replace the fuse with a 20 amp fuse. When you smell burning wire, let off the brakes or turn off the lights or just stop doing what you just did, unplug the 20 amp fuse, and go replace the wire you just fried.

Do NOT try this trick with fuel related circuits.