No Brake Lights

[dvor316]

I have an 03 F250 SD 7.3. I found out that the brake lights are not working at all. I checked fuse #34 for the brake lights and it was ok. I replaced the switch on the pedal and no brake lights still. I checked the new switch and the blue/black wire has power but when the I pushed the pedal and checked the pink wire it did not have power.
I am not sure where to go next with diagnosis of the problem. I searched the forums here and other Ford sites and didn't find anything that would help. I can't drive it without brakelights without risking an accident or ticket. Any suggestions? Thanks

 

[DaveBen]

Check out the four way flasher. The brakes go through the flasher. Sorry I don't have the wiring diagram for your truck.

Dave

 

[Frankenstien]

Been there done that.... brake switch, by the peddle.... around 20 bucks, about a 10 min fix.

 

[dvor316]

Thanks Guys,
I went out and had my wife stand behind the truck to check the brake lights when I used the brake controller to see if the worked. I steppped on the brake pedal and she said they were on before I even touched the controller.
She did say that the 3rd brake light on the cab was out so I will check it and replace the bulb if necessary. I hope this is the end of the brake light troubles. I had already replaced the pedal switch but that did not fix the issue.
The fact that after replacing the switch I did not have any power coming out of the switch when activating it is troubling. Does the Cruise control switch have anything to do with the brake circuit?

 

[DaveBen]

The brake switch turns off the cruse control and puts is in stand by.

Dave

 

[Tail_Gunner]

Check the turn signal switch in the column. Specifically, ensure the wire harness plug is not coming loose from the switch.

The wire pathway going to the rear end for a brake light is the same as the turn signal. The only difference between a brake light and a turn signal light, is the turn signal flashes, the brake light don't. It's the same circuit pathway for either and the same light bulb filament. Another thing to realize from this, since there are two separate wire circuits going to the tail light for the left turn signal/brake lamp and the right turn signal/brake lamp, if both brake lights are inoperative (unless you have a cut wire harness) the likelihood of having a wire problem going to the truck's rear end is nil. Your problem is most likely up front somewhere.

Earlier this year, I was having problems with my turn signals. (See HERE) My problems were extremely intermittant. At one point the brake lights worked. Later on, when I checked again, they were not.

As you can see in my previous post, the locking tabs which held the connector to the turn signal switch were broken off. I had to fabricate another way of securing the plug to the switch assembly.

I made another post HERE outlining how I disassembled the column to access/remove the turn signal switch as well as modifying the turn signal cancellation cam so the turn signals wouldn't cancel everytime you make a lane change.

Hope this helps you locate the problem.

 

[JLDickmon]

yay Kent.
well, not yay for having turn/brake light problems, but
yay remembering the threads to help the guy out.

the turn signal/wiper/dimmer/hazard multi-function switches on Ford products in general are pretty good, but failures do occur.

It's less than an hour's job to change it (including cracking the obligatory beer). You do not have to pull the steering wheel.