Good afternoon or evening. I am having an electrical issue on my 1962 F100. I will do my best to explain this:
-with the lights on my license plate light goes off when I apply the brake and it flashes when I use my left turn signal.
-with the lights off the license plate light goes on when I hit my brakes.

Something is messing with that signal as it travels through the license plate light connection on its way to the left brake/turn light. Is there something under the dash that would control that. Could I splice another wire to the license plate light in line with the headlights?

Any help or tips would be great. Thanks for your time.

 

Sounds like you have a cross wire on the plate light
Plate light should be connected the the brown wire only
Yellow and green are brake/turn

 

The plate wire does attach to the brown. The brown seems to continue on to the passenger side. I guess I need to track where it goes after the plate. Wish me luck! Thanks for you input.

 

I suspect you may have a trailer light connection mumbo jumbo mess, that is usually where the rear light issues are. Do you have a circuit tester with a light bulb in it?

There should be a factory connection just past the end of the drivers side frame rail. You can disconnect and check there also.

With everything off pull the light switch out one click. That should have power going to the tail/license plate light. You should be able to resolve it from there.



John

 

From the description it sounds more like a bad ground. There may be a short in one of both of the tail light sockets as well. Sounds like the brake lights are using the license plate as their ground path. Not to say there aren't other issues with the truck's wiring as mentioned by previous posts.

I would remove both tail lights and double check the ground connections. I don't remember whether there is a separate groung tail off the light housings or whether they ground through the light housing itself. Either way, make sure there is no corrosion or rust and that connections are clean, shiny metal.
Also, make sure the light sockets are free of corrosion and in good repair.
When you put things back together use a dab of dielectric grease at the connection points to help fight future corrosion.

I would do the same at the license plate light as well, just as a preventitive measure.

Running an additional ground wire from the frame to the box is also a good idea.

As an afterthought, a bad lamp could be the culprit. I would replace both tail lamps with new, or known good and see if the problem persists.

Roger Carter

 

So I have discovered I have three wires heading to the rear of the truck- yellow, brown and green. Yellow goes the left taillight and brown heads to the right. The brown is where the PO spliced of for a feed to my license plate light. I have found two random yellow lights that do nothing at the rear of the truck. On seems to have a constant 12v feed and the other was clipped off under the hood. Did they make the 62s without a license plate light? Any AZ people know if this can be grandfathered in?

 

Correct 3 wires going to the rear l & r brake & turn signal shared, and the tail/license plate wire.

Don't know what some PO may have done. Read the last sentence in my last post on this. That 3rd wire should be delivering current to the rear with the switch pulled out one click.


John

 

I can't get any power from the yellow or green. Only brown gives me a reading. I rerouted the plate light straight to the frame and it works properly, but then I had both blinkers come on when when I hit either right or left turn. I am thoroughly confused but now it functions properly although the lights brink much much faster than before. What I would give for someone local that knows auto electric and could help me out. But I'll take the half victory for now. Thanks for all your input guys.

 

I started a help thread for you in the Arizona Chapter forum. It's not complicated but if you don't have a clue, you don't have a clue.



John