I have an 85 ford f150. I have no dash lights and no taillights, plugged in new switch and no change. I used a test light and no power to instrument light wire or taillight wire all other connections check out OK. I am at a total loss as to where to go next, I would appreciate any suggestions. Please help me.

 

hey
check your fusible links, they are on the passenger side connected to the starter solenoid.
they are fatter sections of wire with little tabs on them.
pull on them to check.
also check the eye connectors on the solenoid too
I had the same problem and that's what it was.
there are three of them.

 

Both of these circuits run off the taillamp fuse in the fuse box. Check for power at the fuse. If you have power at the fuse and the fuse is good, then go back to the headlight switch and check the tan/white wire. This is the wire that feeds the taillight/cluster circuit to the switch. If you do not have power on the tan/white, but had power at the fuse, then the tan/white wire has burnt in two somewhere. This is a common thing that happens on these trucks.

Usually the tan/white has melted right at the headlight switch connector.

 

You are correct, the blue/red does feed all the dash lights. That power comes from a fuse in the fuse box. But that fuse is not fed from the battery or the keyswitch, that fuse is fed from the lightswitch. The blue/red is tied to the brown wire inside the light switch.

The brown is for the running lights, the blue/red is for the cluster lighting, and both of these get their power through the lightswitch and that is fed with the tan/white wire. If the tan/white wire has no power at the switch like you said, you are sunk on the others.

I don't think you said if the tan/white fuse was any good or you have power there. Go down to the fuse box and find the fuse that feeds the tan/white and check for power. According to my book it's fuse #8, "parking and tailight" fuse.

If you have power at fuse #8, and the fuse is good, then you have a problem somewhere in the tan/white wire. You may have to run a new wire.

 

I went out and did further checking and I found that both fuses were blown. I don't know if there is a problem with one of the wires or not, but put everything back together. I didn't try it after everything was back together, as it is warm and muggy outside and I want to wait until it cools off later to try it. if there is a problem with one of the wires can I bypass it by running a different wire. I will come back later when I find out. Thanks for the reply.

 

If fuses are blowing, you have a problem obviously somewhere. That's the trick, finding the problem.

Put the proper size fuses in place. If the instrument cluster fuse blows only, that means there is a problem in the blue/red wiring. The first place to look is the stereo. There is a blue/red going up there to light the original radio dial, and people do not hook this wire up to the correct thing, or their wiring is very sloppy and this blue/red at the stereo can get into trouble.

If just the taillight fuse blows, the cluster fuse stays good, then you have a problem most likely on the brown wire. The problem is, this wire goes all over the truck from front to rear, feeding the running lights in the fenders and the grille area, and the lights at the rear. The first place to look for a problem is at the rear, where people hook in trailer plugs. Also look for anything added like running boards with little lights or any other little added running lights.

Do you see a theme in the above post? It's true, when people go modifying their wiring, that's the first place to look for problems. They do not make very good connections, and they do not tie the wiring up out of harms way and install bushings against sharp edges. It causes a lot of trouble with any vehicle, but it's a simple thing to be aware and follow good wiring practices to avoid problems.

 

Hi, I went out a little bit ago and checked all of the fuses for the different lights, and the only fuse I found that was blown was the fuse for the dash lights. The stereo that I put in the truck is not connected to any of my lights, it gets it power from the fuse block. one power wire has power all the time and the other wire is connected to the accessory fuse in the fuse block. I was thinking about bypassing where the problem is by running a wire from the light switch to the fuse block and then from the fuse block to the instrument pack. I would appreciate your thoughts on this problem. I also would like to thank everybody that replied to my first thread.

 

Don't mistake "by passing the problem" with "feeding the circuit from another source". The later will just blow the fuse of the new feed circuit and take out something else.
First you have to find the location of the "short" before you can bypass it.
Good luck.

 

What did you do with the blue/red at the stereo? I know you said you have power for the radio going somewhere else, but I would go back up there and find that blue/red. It could be laying somewhere up there and touching something metal. That's the first thing I would do.

Adding wires will not help a fuse blowing problem.

 

Im having a similar problem on my 1999 f150. no dash tail or parking lights. i had a blown fuse under the hood for the lights replaced it and it blew again right away. i checked my stereo wiring because i installed a new one a couple months back that all still looked good ill check the trailer plug after work.