Brake light problems

[nutznky]

A few weeks ago I was considering buying a 97 TJ with a 4 banger for my wife. I held off and found a steal on a 00 model with the 4.0 5 speed. The jeep only has 98,000 on it and runs like a top. The other morning I was driving it too work and my neighbor was behind me and at the end of the street flagged me down and said my brake lights were out. The third brake light is working and so is all the other lights, turn signals, parking lights, back up lights and so on. All the fuses are good. The only thing I can figure is the switch on the brake pedal. Anyone else had this problem and anything else I should check. I'm not good with electrical at all so I really don't have any other ideas. Thanks in advance.

 

[Jester32]

Either both bulbs or a bad ground. Could have been neglected one went then the other. See it all the time.

 

[Jester32]

Is there trailer wiring?

 

[nutznky]

Yes it's wired for a trailer. I also just noticed the hazards are not working either. Now I'm thinking it may be the turn signal switch.

 

[Jester32]

Check your trailer wiring for corrosion. The one thing brakes and hazards have in common is direct battery feed. The turn signals are ignition.
If you can disconnect the trailer wiring try that. If its own then just check for corrosion. I would check for power in and out of the brake switch see if you are getting direct. Then check your grounds.

 

[nutznky]

I have also read that the power for the brake lights runs through the multi function switch( or turn signal switch for us simple folk)lol. Is this not correct? Again when it comes to electrical im lost.

 

[Jester32]

I can look at a schematic when I get to work tommorow for you. I'm not sure on that one but a wiring diagram is an easy answer.

 

[nutznky]

Thanks for your help Jester.

 

[808CJ7]

I'd check the bulbs first. You said the third brake light is working, so the switch at the pedal should be ok. The turn signal uses the same filament as the brake light

 

[SteelHeadz]

Wiggle the hazard lamp switch and see if that intermittently works. I've seen issues with that from the past with a concern of no brake lamps or turn signals inop. The hazard switch is part of the multifunction switch if i remember correctly.

 

[Jeepergeo]

If the third stoplight works its not likely the pedal switch.

First, make sure your neighbors observations were indeed correct. Then check the bulbs. Then check the grounds...an easy way to check grounds is to run a supplemental grounding wire from the brake light directly to a known good frame ground.

 

[nutznky]

Got it fixed. Evidently the third brake light is on another circuit or something. The problem was the multifunction switch(turn sign signal switch). It was dirty and and not getting good connection. I wiggled the hazard switch around and sprayed some contact spray on it and presto, brake lights are now functioning properly along with hazards. Kind of a screwed up set up if u ask me. Who would ever think that switch would control your brake lights. Thanks to everyone for the suggestions.