Brake Light Fuse Blowing

[MarYJac04]

I have a 2000 Ford 53 series chassis that is blowing the brake light fuse. This is the third or fourth time I am having this problem. The first time, I thought the 4 wire tow connector had a problem and after working on it the problem, it went away for a few weeks.

Since then the problem has returned several times, each time the problem goes away after moving the towing cable harness around as well as the cable at the brake pedal switch. I can travel for a few days without problem, but after the coach sits without moving for a few days it returns.

Now I am getting ready to travel tomorrow so decided to check the lights and have the problem again. I have removed the tow connector, cut the wires and insulated them, disconnected the two coach connectors for the chassis lights at the rear of the coach, and the fuse blows immediately when the brake pedal is touched. I cannot think of anything else to disconnect.

I am beginning to wonder if it is possible for the switch on the brake pedal to short internally to cause the problem.

Any help is greatly appreciated.

[hermanmullins]

MarYJac04,

You have a short somewhere that is for sure.

First, without hitting the brake, put in a fresh fuse and try the turn signals. If they both work then the short will be somewhere in the brake light switch or turn signal switch. Many thing in the light system run through the turn signal switch.

But you must have a bare or burnt wire somewhere.

Good Luck

Herman.

[MarYJac04]

Both turn signals and emergency flashers work until the brake padal is pushed. Fuse blows immediately.

[dickandlois]

Need to ask if your Coach has separate four way-turn signal (Amber Lights) and red brake lights?

That being the case, I would look for a short in the brake light circuit. You can make a test circuit by installing a light bulb in place of the fuse using a blown fuse and connecting a light bulb across the fuse blades.

Just drill a hole in both sides of the fuse, place a wire in each hole. Use a wire size close to the hole size so it contacts the side on the holes.

Depress the brake pedal with something to keep it depress, work on the wiring for the brake lights and when the bulb goes out you have found the location of the short..

Good luck Rich.

Patent Pending !!!

[hermanmullins]

Rich,

Sound like a neat tool. If you leave it in place too long you could find the short by the smoke.

Herman

[vtbigdog]

Are you sure the fuse you are replacing is the proper size? You may not have a short, but rather the wrong size fuse installed.

[dickandlois]

Herman posted: "Rich, Sound like a neat tool. If you leave it in place too long you could find the short by the smoke. "

Herman, One never gets smoke !! The bulb just gets dimmer or brighter. And when one finds the short no more light in the bulb or LED.

So the magic smoke stays in the circuit and you know how hard it is to put the smoke back in.

Rich.