02 F-350 4x4

[andrewlee]

Just recently my brake lights and turn signals stopped working. My running lights still work and all the fuses and bulbs are still good. I checked all the wiring for the trailer wiring harness and it all seems to be in good shape. I am at a loss for what to check next. Any and all help will be greatly appreciated.

[Franklin2]

The piece that is common to both rear turnsignals and the brake lights too, is the turnsignal switch. I can tell you what wires to check in the steering column if you want to do a little bit of testing, or you can just try replacing the switch.

You also might want to try tilting the column if you do have tilt, and see if they try to work. Occasionally there is a plug in the column that gets halfway pulled apart because of strain on the wiring, and tilting the column will sometimes relieve the strain.

[andrewlee]

Thanks for the information. If you could tell me what wires to check in the column and I will check them and try the tilt on the wheel.

[andrewlee]

I tried the tilt on the column that didnt work. If the turn signal switch was bad would it only affect the rear turn signals and the brake lights and the front still work? My front turn signals and front flashers still work. Only the rear turn signals and brake lights dont work.

[Franklin2]

Originally Posted by andrewlee

I tried the tilt on the column that didnt work. If the turn signal switch was bad would it only affect the rear turn signals and the brake lights and the front still work? My front turn signals and front flashers still work. Only the rear turn signals and brake lights dont work.

Yes, that's it exactly. The rear turn bulbs and the rear brake bulbs are the same bulb. So they use the turnsignal switch to juggle the flasher signals and the brake switch signals to these bulbs.

[andrewlee]

What wires on the turn signal switch do i need to check. I looked up the part at o rileys and it is 90 something dollars. Is there a way to repair the switch and the wires or is it internal to the switch?

[Franklin2]

The signal from the brake switch comes in on a lightgreen wire. Test this first, you should have voltage on this wire when you push the brake pedal.

Make sure the switch is in the center position. There should be a orange/lightblue and a lightgreen/orange wire that leaves the switch, and goes back to the brake/turn lights. You should have voltage on both these wires when you push the brake pedal, with the switch in the center position. If you had it coming in on the lightgreen but have nothing coming out on the other two wires, then the switch is bad.

[andrewlee]

I will test the wires when I get off work. Thanks for all the help.

[andrewlee]

I just tested the switch and I have power in and power out on both wires. Do you have any more ideas of what it could be.

[Franklin2]

These two wires leave the column and go to the rear along the driver's side framerail. You must have a wiring problem between the column and the rear lights.

[andrewlee]

I will start tracing out the wires. Thanks for all your help.