06 kj rear brake lights issue

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AngriezJeep

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Ok, I just bought this thing and didn't look too close. Should have done a light check. Too late "shrugs"
Here is the issue: none of the rear lights turn on when I got the brakes. Neither the two mains or the CHMSL.

I replaced the brake switch (it was 20 bucks) and that didn't fix it. The rear passenger comes on when I turn on the marker lights (fuse 7 is blown, so the right marker lights won't come on, and I don't have a spare right now). All the other lights not mentioned function (reverse, turn, hazards which flash the turn).

Next step when I get my tools home Monday is to check the bulbs, but it seems VERY unlikely that all three all burnt out, especially since the right tail light works when the lights are turned on (is it likely that the brake Element is the bulb I burnt out)

Where do these ground at? And does anyone have any suggestions?

Note: both lense units have cracks and one has a Lot of condensation in it.
 

KJowner

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You need to get in there with a multimeter and see what's going on. Does it have a towbar? On mine the wiring for the tow electrics is spliced into the left hand light, a fault here could cause all sorts of problems.
 

AngriezJeep

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No, but there previous owner did wire it for a subwoofer that isn't there. I have a multimeter. Monday I'll bring the tools home from work. I assume I should check at the base of the plugs to see if they're getting signal.
 

Billwill

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Download the Service Manuals for your year KJ....Section 8W has the Logic Diagrams for you to be able to climb in with your Multimeter!
www.colorado4wheel.com/manuals/Jeep/KJ
What year/model is your KJ?

If your Year is not listed try a manual near to your year although then the wire colors may not be correct.

Edit: Link not working for me....got something misspelled I think! Will try fix it!
 
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sota

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not for nothing but, did you check/change the bulbs?
the fact that you have some of the lights working on both sides, means the grounds are fine.
also means some of the bulbs are fine.
fix the fuse, change some bulbs, and go from there.
it's amazing how many vehicles I see with 2/3 brake lights not working. it's even more amazing how many I see with NO brake lights working!
 

seafish

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In fact ALL lightbulbs have a definite lifespan and the same type of bulb, running for the same amount of time (every time you step on the brakes) can and do burn out ROUGHLY around the same time, often within a matter of days or weeks of each other.

For instance, just last month, my daughter and I replaced the left brake light (dual filament bulb but the brake filament burns brighter/hotter)on her 2000 Honda CRV...an easy job and also a simple learning experience for her. The very next week when she came to visit, the right side was burnt out and she replaced it by herself, also learning another lesson that sometimes it is better to replace the same functional type of bulbs in pairs. Ive also had functioning halogen headlight bulbs burn out within a couple weeks of each other.

All that said, though it would be easiest and cheap enough to simply replace all three bulbs and see if the problem is fixed, the fact that you ALSO have a fuse blown from unknown causes is hinting at a potential wiring problem...like others have said, a DVM will help you get to the bottom of it.

Also be sure to also keep an eye out for corroded connections and dampness that might be a sign of water intrusion.

Just my .02
 
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AngriezJeep

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not for nothing but, did you check/change the bulbs?
the fact that you have some of the lights working on both sides, means the grounds are fine.
also means some of the bulbs are fine.
fix the fuse, change some bulbs, and go from there.
it's amazing how many vehicles I see with 2/3 brake lights not working. it's even more amazing how many I see with NO brake lights working!
AFAIK the same bulb is used for brake and running lights (looking online for replacement housing, all had three slots: backup light, turn indicator, and the brake/tail light) That why I am a little confused on why I get the light on the right side (as I said, I know I have a bad fuse I can't replace until payday for the left one). But as I said elsewhere, Monday I am bringing home tools to access the lights and see what's up as far as power. Are these bulbs dual filament? The CHMSL coul be. Burn out. We shall see
 

AngriezJeep

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In fact ALL lightbulbs have a definite lifespan and the same type of bulb, running for the same amount of time (every time you step on the brakes) can and do burn out ROUGHLY around the same time, often within a matter of days or weeks of each other.

For instance, just last month, my daughter and I replaced the left brake light (dual filament bulb but the brake filament burns brighter/hotter)on her 2000 Honda CRV...an easy job and also a simple learning experience for her. The very next week when she came to visit, the right side was burnt out and she replaced it by herself, also learning another simple lesson that sometimes it is better to replace the same functional type of bulbs in pairs. Ive also had functioning halogen headlight bulbs burn out within a couple weeks of each other.

All that said, though it would be easiest and cheap enough to simply replace the bulbs and see if the problem is fixed, the fact that you ALSO have a fuse blown from unknown causes is hinting at a potential wiring problem...like others have said, a DVM will help you get to the bottom of it.

Also be sure to also keep an eye out for corroded connections and dampness that might be a sign of water intrusion.

Just my .02
Thank you. And yes, that does make some logical sense. If I replace the fuse and that tail light lights up when the brake is pressed, then it's time to do what I initially wanted to do, replace it all with LED. I may have a certain bias when it comes to the troubleshooting, which means I probably discount the bulbs being dead completely. It just seemed unlikely statistically they'll be out at once.
 

AngriezJeep

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Deb'nKJ

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Yes they are twin filament bulbs, so it could well be tat only the higher wattage filament has failed. From memory, the other rear bulbs are too, although only one is used, so swap one gf those for the brake/tail & see what happens.

The sockets on KJ's are infamous for getting hot, distorting the plastic & losing a connection.
 

Billwill

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What I have often done....since my wiring got damaged after my GF hit a tree that jumped in front of causing lots of wiring damage....is to tape a small pin or needle to the Positive probe of the meter.

Then with the Negative lead taped onto ground somewhere....pierce the insulation of the lead that should be carrying Plus 12 Volts to the bulb....should show +12 volts if the lamp has been turned ON!

Close up the hole in the insulation made by the Pin/Needle with some glue to seal it from water ingress!

Then remove the bulb and place the Positive lead onto the contact for the bulb....there should be +12 volts on that contact and inspect the contacts to check that they have not melted themselves down into the surrounding plastic....out of reach of the Bulb Contact itself.

Then touch the Negative Meter Lead to the side of the Bulb....should be negative at all times and put the Positive lead to the Battery positive stud....should show 12 volts if the grounding to the bulb is good!
 

sota

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Thank you. And yes, that does make some logical sense. If I replace the fuse and that tail light lights up when the brake is pressed, then it's time to do what I initially wanted to do, replace it all with LED. I may have a certain bias when it comes to the troubleshooting, which means I probably discount the bulbs being dead completely. It just seemed unlikely statistically they'll be out at once.
You know what one word in the english language has been a pox on actual learning? Statistics.

There are Lies.
There are Damned Lies.
And then there's Statistics.

Experience has taught me, if something isn't "statistically" likely to happen, then it DEFINITELY happened. :D
 

AngriezJeep

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So update: I got a replacement fuse. The DS license lights up fine with the marker lights on. So I got the tools to open the lights. Th DS had a burnt out Element on the bulb. The passenger didn't not. I swapped them just to see that would happen. Answer? Nothing. Still no brake lights.

Opened up the CHMSL and discovered why it isn't working: no bulb.

So... Still don't think it will work if I get a bulb but willing to try.

And what hair brained engineer at Chrysler designed that idiotic, overcomplicated light housing setup?!? I am seriously looking at just buying these to replace them outright:

https://a.co/d/cxwGvan
At least they have individual wires to the different lights.

The old housing aren't weatherproof anymore anyway. I'm fact the brake contact may indeed have melted into the body of the housing. The same contact on each side was a bit "meltier" than the others. These might just fix the issue

On a side note: here are pictures of my fuse panels. As far as I can tell, I'm missing a relay on the top of my inner fuse panel. It apparently is for the DRL. Insanely vital?



And a simple, I feel like an idiot question: where the hell is the fog light switch?! It's obvious my Jeep has them, but I cannot find it...
 

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Jeremy-WI

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DRL don't work right on US models as far as I know. To turn the for light on, turn the headlights on then pull the end of the switch out towards the door
 

Duster

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I would check and see if the 3rd light up top is working or not.

I yanked my 3rd light bulb and replaced my light housings and turned my brake light bulbs the one way... the bulbs have 2 filaments and there are 2 positions they can be installed in as far as which way they are turned. I figured out one of the two burns out if installed the one way after replacing the one bulb several times. I finally got mad and was like what is different? Why are the rest original and this one keeps burning out? Once I took another out I noticed the different orientation. I haven't lost a bulb in the lower housings since.
 
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