Hi everyone -

I've been searching the archives here for the past few days trying to find a solution before I bothered you all with my questions, to no avail.

I have a '79 Ford F150 that I use for work and recently, my brake lights went out. I replaced the switch, bulbs and fuses and still nothing. My headlights, indicators and tail lights all work - it's just the brake lights that are failing. However, if I turn on the hazards, the brake lights come on!

Of all the suggestions I've read from the archives, the multifunction switch is the next thing to check. Before I go ahead and do that, does anyone here have any other suggestions I should try?

And I've tried to find the fuse box diagram for this truck and have been unable to find it. Any help would be appreciated before I end up having to take it to Ford.

Thanks in advance!!

Sandy

 

Is there power at the brake lamp switch......sometimes the wires look like they are there but the wire may be broken this will also tell you if the fuse is blown......

 

Sandy, I'm assuming you have a test light, or a volt meter (a light would be easier to use here). You already know that the bulbs work and that the wiring from the MF switch to the tailights is good. Trace this way, one side od the stoplamp switch should have power all the time. The other side should have power when you depress the pedal. Note the color of this wire. Access the connector on the MF switch, check for power going into the MF switch when depressing the brake pedal. If there is none, you have a broken wire between the stoplamp switch and the MF switch. If this is OK, I would say chances are pretty good that the MF switch is bad since your hazards work, they send power along the same wires.

 

Thanks Momalle - I'll try that tomorrow when I have some light, and report back!

 

Problem solved!!! There was a short between the fuse box and the brake light switch. The wire was broken at the connector! It was very hard to see, but testing with the test lamp showed there was no current going out of the switch.

Thanks so much for all your help fellas!