I have a 98 F-150, 4.6 and just found out that my brake lights are not coming on when i press on the brake pedal. The lights themselves work when i turn on my headlights and when i go in reverse. Any suggestions where i can look at would be appreciated.

 

checked the bulbs?.. they can be out.. maybe even the fuses that power the brakelights.. check the socket of the bulbs also they can be bad too..
Last.. i doubt it.. but check the brakelight switch.. on top of the brake pedal.. right on top.. could be disconnected or bad.. bulbs should be the 3157s

 

Well, the bulbs and fuses looked fine. i disconnected the switch above the pedal and it seem to look ok. I took a paper clip and folded it in a "U" shape and connected it into the switch to make contact to test the power and my brake lights came on. I connected the switch back and when i stepped on the brake, the brake lights came on??!!:fyi:

I don't know if it was dirty in there which is why it wasn't getting power or what but after sticking the paper clip in there just to test it, it seemed to help.

 

Could have been dirty contacts.

It may be that the switch is out of adjustment with the pedal, and the jiggling around you did got it back close enough to work.

 

The switch is called the BOO switch for 'brake on brake off' if you need to order a new one.

 

I am having a similar issue. I tested power to the brake light socket and there was power to the blinkers but the brakelights didnt work BUT the third brakelight does. I put in a new brakelight switch and thatwas a no go. I would like to try what this guy is talking about by cleaning the plug but if my third brakelight works then will it make a difference? ive been driving around with no brakelights for about a month.... Well ok with just a third brakelight.