Hi guys, my problem is this. I just discovered that my rear tail brake lights don't work. The third light works okay, but brake tail lights dont work, even after replacing both bulbs. I also checked the fuses, but all are okay. This one is new to me, as simple as it sounds I didn't think it could have been more complicated. Any help would be appreciated.

 

I am assuming the rear running lights work when you turn on the headlights?

Do the rear turnsignals work? They use the same circuit and bulb filament as the brake lights. If the rear turnsignals do work, then I would suspect your turnsignal switch(ford calls it a multi-function switch) is bad.

 

Thanks, but I replaced that a couple years ago. I forgot to mention that my truck is a 1999 f150, lariat, 5.4 v8. All the other light work including the signals, Parklight and reverse light, that was why I bought the new bulbs, well supposedly new. Is it possible that the new bulbs # I think was 3157 and the tech(c.t.) gave me 3157kr. Said it was the same. I jammed a piece of two by four against the brake pedal and against the floor. I even started it up, turned on running lights, headlights, flashers, put into reverse, nut no luck. I can't seem to come up with this one.

 

You have the brake light signal from the pedal that comes into the turnsignal switch. The third brakelight works, so you know the pedal switch works.

The turn flasher signal also comes into the turnsignal switch.

Both the turnsignal flasher signal and the brake signal are mixed together in the turnsignal switch, and then they run out on the same wires and use the same bulbs all the way to the rear.

So if your turnsignals work, your bulbs and wiring from the switch to the rear are ok.

You may have a plug coming loose in the column, or something around the switch is bad. But everything is pointing to that area.

 

I finally had to take her in to the dealership. My original intention was to buy another combination/multifunction switch. But dealer said if I bought it and I still had a problem, I couldn't take it back, so I took it in. The problem turned out to be the connector that plugs in into the mfswitch was bad. Two hundred and thirty dollars(cdn) later, $179 labour $50 for parts etc. So thanks a lot Franklin2 you were on the right track.