Howdy folks!

Need a little help on this one.
01 Supercrew and the brake lights in the rear don't work. Flashers, signals, and tail lights work so its not the bulbs or wiring. The third brake light on the cab works. Fuse in dash is good. Are there two circuits for brake lights? Anything under the hood? I don't think it's the switch since the third brake light works. Any help would be appreciated.

Thanks,
Andrew

01 Screw Lariat

 

It sounds like a bad multifunction switch to me, or a bad wire going to it. If the 3rd brake light works, the brake pedal position switch is working, and if the turn signals work, it sounds like the BPP signal either isn't getting to the multifunction switch, or isn't getting THROUGH the MFS. I'd start by checking for power at the switch in the light green wire when the brakes are pressed. I'f you're getting power to the switch, the switch is bad. If you're not getting power, you may have a bad splice between the brake pedal switch and that wire, and a jumper should be able to correct that without too much trouble.

-Joe

 

Joe thanks for the reply! Is the MFS the switch for the lights on the dash? I have power on the light green wire coming off the connector on the brake pedal when the brake pedal is pressed. The harness plugs into what I would guess is the BPP switch. It is connected to the rod through the firewall and held on with a yellow pin. I haven't checked at the dash switch. I will try to pop it out tomorrow and check. Thanks again!

Andrew

01 Supercrew Lariat

 

Well yesterday i had to replace the left side bulb I noticed on my way to work when I made a left turn the turn signal went real fast so when i got home I went to check to see if the front signal was out as I heard our trucks if you have a auto tranny you can't get it out of park if one of the brake lights don't work and you have to shift to nuteral and what not in order to get anywhere until fixed well on my truck that did not happen so I figured it was the front but turned out being the tail light that was out so I replaced it last night just glad no cops seen me when I only had one brake light working as the 3rd one hasn't been working for a while and I just haven't gotten around to getting a bulb for it yet and forgot to get one when I bought the one for the left side tail light.

 

The MFS is the turn signal/wiper switch. It's located on the steering column. I would have suspected that you had power on the BPP switch as without it the third brake light would not light either. If I remember correctly, if you remove the trim around the lock and hazard switch, you should be able to unplug the harness and check for power at the appropriate terminal without removing the switch itself, but don't quote me on that.

-Joe

 

Holy Run-On Sentence, Batman!!! Please use some punctuation in your posts.

The only way the park-shift interlock will fail is if the interlock solenoid itself fails and sticks, if the brake pedal position switch fails, or if the fuse that feeds it blows. In that case, unlock the column without turning the ignition on, shift into neutral, start the truck and drop it in gear. I'd then recommend driving to a place that can fix it or supply you with the appropriate parts.

-Joe