Brake Lights not working, everything else is!!!

I realize I'm three years late on this thread, but I'm new to Jeeps (and most mechanical work) and am having the same issue.

Please forgive the ignorant question, but what is meant by "check the grounds"?[/QUOTE
Ignorant questions are happily received here,That's how we all learn from each other. The ground for example,on the negative side of your battery the cable is attached to your engine block,that is a ground wire. Checking it means to disconnect it and give it a thorough cleaning to make sure you have a good connection. Perhaps others here could chime in and give an example.
 
I realize I'm three years late on this thread, but I'm new to Jeeps (and most mechanical work) and am having the same issue.

Please forgive the ignorant question, but what is meant by "check the grounds"?


Electrical of course involves a positive and a negative. The positive side is the power flow from the battery or power source to the item, such as a bulb. After the bulb is powered the electricity needs to return to the power source to complete the circuit; this is the negative or “ground” side of the circuit and without it you have nothing. On most vehicles rather than running a wire to and from the battery to the item to be powered only the positive side has a wire that can be traces back to the power source (through the fuse block) then the return side (negative) will be “grounded” to the metal body components or frame close to the item’s location making the body or frame the return wire; there may be several ground contact points along the way back to the power source. Most often the ground is a wire attached to a sheet metal panel or the frame with a screw or bolt. These connections can become corroded with time and exposer to the elements. It never hurts to clean up the connection even if this isn’t the entire problem. As far a turn signals and stop lights are concerned there are switches that may also need attention to alleviate a problem.
 

I am having a similar issue on my 2004 Rubicon. I have headlights, tail lights and turn signals. I have checked the fuse which was fine. I confirmed that the brake light switch (which is activated by the brake pedal) has continuity and functions properly (put continuity tester on and pressed and released the switch to confirm proper function). I have looked at the wires back to the rear lights and can find nothing that looks wrong. I removed the tail light covers and inspected the socket as well as everything else. It all looks perfect. No moisture, corrosion or dirt. Although I do wheel my Jeep I take very good care of it and it is very clean and no damage. I also put my OBDII on it and checked for any codes and have none. I checked the connections on the PCM harnesses which are cleaned and snuggly attached. But even after checking all these systems I have no brake lights!

Any suggestions would be appreciated.
 
I am having a similar issue on my 2004 Rubicon. I have headlights, tail lights and turn signals. I have checked the fuse which was fine. I confirmed that the brake light switch (which is activated by the brake pedal) has continuity and functions properly (put continuity tester on and pressed and released the switch to confirm proper function). I have looked at the wires back to the rear lights and can find nothing that looks wrong. I removed the tail light covers and inspected the socket as well as everything else. It all looks perfect. No moisture, corrosion or dirt. Although I do wheel my Jeep I take very good care of it and it is very clean and no damage. I also put my OBDII on it and checked for any codes and have none. I checked the connections on the PCM harnesses which are cleaned and snuggly attached. But even after checking all these systems I have no brake lights!

Any suggestions would be appreciated.



We have have the same car, and are experiencing the same problem. Please tell me what was wrong with your car and what you did to fix it please. Pictures are also very much appreciated at this point. Thanks!
 
The electrical system uses the "ground" to complete the circuit. Think of the electrical system on a Jeep (well, everywhere else too) as big circle: the voltage leaves the "+" post of the battery and must return to the "-" post to complete the circuit or flow of energy. In this case, the metal tub and frame or "chassis" (which conduct electric energy)of the jeep are connected to the "-" or negitive side of the battery via a large wire and grounding straps. He is referring to the black wires (usually black anyway) that come off the light housings or other devices that are screwed into the chassis. They sometimes corrode, get fouled or brake off. When this happens, the circuit is open or broken and the energy cant flow back to the "-" side of the battery.
 

I was wondering if there was something that is commonly at fault with the Jeep Rubicon. We're experienced electricians so we know what we're looking for. Unfortunately we don't have any schematics of all the switches it goes through, I've been able to piece most of the information together from older model jeeps. I've taken off the brake light assembly and inspected the wires. There were a few pinched wires that had some minimal exposed wiring that we thought might be the cause. We spliced those wires back. Nothing. No brake lights, checked the fuses both visually and for continuity, they were all good. Checked the bulbs. Filaments look good. Replaced bulbs just in case. Still no brake lights. Took apart the steering column to look for pinched, broken, burnt, loose or corroded connections. Nothing. Grounds all check good. Cleaned connections just in case, nothing. Ordering a new turn signal switch to try swapping out. Other than that it sounds like the hazard switch. Not sure if "Spud" ever found out what was wrong with his Rubicon.
 
Sorry for the over explanation......... I was reading over all the postings for this thread and got confused. Someone else asked "what is meant by check the grounds?".
 

grounds are the connection to the body which flows back to the battery negative. For DC (Direct Current) electric items to work you need 2 things. Positive going in and ground coming back. Take away either and it doesn't work. Loose/corroded grounds inside the bulbs and at the body connections are the worst.
 
All other lights worked. Fuses got blown for tail lights and blinkers, but no fuse blew on brake lights when my buddy was diagnosing trailer lights.
It turned out it fried my brake light switch (located on the brake pedal). EASY fix / $15.00 part.
Whoodda thunk it?
 
Have you checked the wiring connection at the top of the brake pedal? I somehow managed to kick mine off one day and it killed the reverse and brake lights.

Hello.. my name is Jon..
I just recently purchased a 1989 Jeep Wrangler YJ..
being 27 years old is has some issues.. All and all very solid Jeep, however the ( Brake Lights ) don't work. After doing some reading.. here, and in other venues, I know believe I have a good starting point.. The weather here.. (Ohio) so far is not cooperating.. As soon as I figure my Jeep's particular brake light issue out I will share it with you.. If you find out first, please let me know your findings...
Thanks.. one and all..
 
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