Brake light trouble
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Brake light trouble
I have a 85 F250 diesel and the right tail light that has 2 wires going to it does not get brighter when the brake is pushed. I checked the left tail light and each of the 2 wires puts 12 volts to the bulb when the brake is pressed. But the right one has one of the wires only giving 1.5 volts and the right turn signal does not work (back or front). I have the generic Chilton manual and have looked through the diagrams and am lost. I am considering splicing into the left wire to get 12 volts to right. Any input is appreciated.
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The key to this is power to one filament with headlight switch on running/park light.
switch off.. power to other filament with T/S on,.
Make sure the opposite bulb filament doesn't get power during this test.
If power is present at both.. you have a dead short in the wiring.
see figure #17 on this page.
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
switch off.. power to other filament with T/S on,.
Make sure the opposite bulb filament doesn't get power during this test.
If power is present at both.. you have a dead short in the wiring.
see figure #17 on this page.
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
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Joined: Jan 2001
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From: Virginia
You could have a break in that wire on that side, and a place to look is the connector at the wiring at the rear of the truck, or any wiring someone may have done for a trailer.
Or you could have a turnsignal switch problem, or a problem in the column wiring.
The brake signal starts at the brake pedal switch, and then goes up to the turnsignal switch. The turnsignal switch is pretty complicated, because it takes the turnsignal flasher, and the brake pedal signal, and mixes them together. The reason for this is one of the wires back at each of the taillights is a turn wire and a brake wire combined. The other wire is a brown, and it's just a simple power wire for the taillight when the headlight switch is pulled out.
You should be able to find that colored wire on the right(the one that is not brown) up at the colum. If you push on the brake pedal with the turnsignal switch in the center, then you should have voltage on that wire. If you do, I would suspect a wiring problem along the frame to the rear. If you don't have voltage, then I would suspect the turnsignal switch.
Or you could have a turnsignal switch problem, or a problem in the column wiring.
The brake signal starts at the brake pedal switch, and then goes up to the turnsignal switch. The turnsignal switch is pretty complicated, because it takes the turnsignal flasher, and the brake pedal signal, and mixes them together. The reason for this is one of the wires back at each of the taillights is a turn wire and a brake wire combined. The other wire is a brown, and it's just a simple power wire for the taillight when the headlight switch is pulled out.
You should be able to find that colored wire on the right(the one that is not brown) up at the colum. If you push on the brake pedal with the turnsignal switch in the center, then you should have voltage on that wire. If you do, I would suspect a wiring problem along the frame to the rear. If you don't have voltage, then I would suspect the turnsignal switch.
Last edited by Franklin2; Oct 26, 2007 at 07:26 PM.
