3rd brake light works, main do not??

[hd-tech]

Hello all - Hope you can help with a strange problem with my 2002 Sport Trac...

I noticed that when I apply the brakes, the 3rd or cyclops comes on as it should but the 2 main brake tail lights do not.

So I checked the fuse and that is fine and manual states that all 3 lights are on the same fuse. The bulbs are good because the turn signal is working OK. I even changed the brake light accuator under the dash and still have the same problem.

I am not sure what else to check. I appreciate all the help. Thanks in advance.

 

[Wiffy]

I hope someone replies soon, I am having the exact same problem. I am going to work on it in the morning and if I figure it out something I will post my findings.

 

[Wiffy]

ok figure this out, I was trying to trace the problem and got no where, I checked the lights every time I checked something. I figured it was the MFS and got so fustrated I just had to walk away. I was so fustrated that I just left the ignition on and the door open. I came back to find the battery dead(it was 4 hours later, I was really mad) anyway, I had to jump start the truck and move it to it's parking spot. Guess what. The brake lights are working now. So I am absolutly clueless. Good luck.

 

[Squirrelmaster]

Make sure to go ahead and replace the bulbs, as they are cheap and it will eliminate one possible cause. While you are doing that inspect the socket for any corrosion or grime (I've had bad sockets do some strange things, though this is probably not your problem), and if neither turns out to be your culprit, begin inspecting the wiring for any cuts or nicks. Also check that the trailer plug is receiving a signal as well.

I'm afraid I haven't had my Sport Trac long enough to memorize the wiring like I have my other vehicles, so that's all I have for you at the moment, but I'll try to think on this some more. And I'll see if I can find a wiring diagram too . Good luck .

Tom

 

[hd-tech]

Thanks Wiffy and Squirrelmaster. I will try leaving the battery disconnected trick to see what happens.

I know it cant be the bulbs because the turn signals work.

 

[Squirrelmaster]

I said this before, but make sure you trace the trailer wiring harness, as the more I've read about brake light issues, the more often I've seen it end up being the culprit.

Tom