brake lights = major frustration

[78CJ7Renegade]

I'm having a problem with my brake lights, everything worked fine until I bled the brakes & forgot to disconnect the battery. I've searched multiple forums and read every brake light thread I can find. It started out when the drivers side rear light went out first (no brake,turn,tail) so i switched light assemblies around & verified both light assemblies worked I then thought it was a bad connection so I unplugged the rear light harness under dash cleaned & when I plugged it back in, now I have no brake lights but turns and tail lights work on both sides. So then I've replaced the turn signal switch, brake switch, bulbs, tail light fuse, even the flasher. I also cleaned the ground screws for light assembly. When I press the brake I'm getting 12 volts at the socket prong (the one for brake) with no bulbs on either side, if I put a bulb in one side press brake I don't get 12 vlts at other light. But again I have working turn signals and tail lights on both sides. I don't know what to check next, any ideas?

 

[SCSEAJAYSEVEN]

Do you have the lights with the 1/4" studs that mount the light to the body? Sounds like you are having a problem with the grounding of the light assembly. Run a dedicated ground from the mounting stud to either a known good ground on the body or frame and see if that solves the problem.

You could just put a temp jumper wire from the stud to a good ground to see if the ground is the problem...

 

[hdgapeach]

^^ X2 on the grounds (or lack, thereof)!!

And save all the parts you replaced. Possibly still good and you might have another chance to use 'em in the future.

 

[Torxhead]

There could be an issue with that underdash plug to the rear light assembly. I have had issues with mine and recently replaced it with an aftermarket one. Sometimes when you push the two plug ends together it will push away a contact breaking the circuit.

 

[GARGOYLEJEEPER]

78CJ7Renegade,
Corrosion is the enemy, it is making your electric signal find ground. Remove bulbs clean shiny bright, coat with battery grease aka dielectric silicone. Remove wires from Packard Electric connectors (as Torxhead said) with very small screw driver, by pressing down tab and pulling wire out, clean shiny bright & silicone, bend tab back insert and fill the back of connector with Perma Tex #2 as per factory. Clean all ground mounts & silicone.
Electricity is like water it will find the path of least resistance.
Use this as part of maintenance before it becomes a repair.
Hope it helps.

 

[Turbogus]

X2 about corrosion and oxidation especially here in the great PacNW. Granted from another forum but this guy specializes in electrics and Jeeps with concise explainations to the Nth degree. He's really been helpful to me when I upgraded the wiring controls under the hood in 'BB'

Been reading the good book of JeepHammer! - JeepForum.com

 

[unabletologin]

Thanks guys for the help I've been unable to log back in to the site to respond. Anyway the fix was corrosion at the fuse block I had put in a new fuse but I guess it wasn't making good contact I wrapped the fuse end with tin foil and the brake lights work. If only I could of done this sooner as I worked on it all week even took out the dash and traced all wires to make sure there was no problems. I just couldn't see how I could have 12 volts at the socket and no lights. Anyway thanks for the help hopefully the admins fix my acct so I can use this site.

 

[Torxhead]

I just couldn't see how I could have 12 volts at the socket and no lights. Anyway thanks for the help hopefully the admins fix my acct so I can use this site.[/quote]

I did have the same issue with mine at the tailights, and just could not figure out why no lights. The problem was corrected as stated in my post above. I did get brighter lights by running a jumper wire from the battery negative to the rear of the body also.

 

[GARGOYLEJEEPER]

Every one,
This is what I use for testing. Of course mine does not have the fancy red coiled cord, but regular black 110v cord. Best $30 I ever spent, I also made a extension so I can get to the back of trailers. Always plugged to the battery since not all cig lighters work, and or may get false reading.
Hope it helps.
Just trying to fix the world one Jeep at a time.