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Running light and tail light out

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I don't know if this is a common problem or not but I'm looking for clues on where to start. My left front running light and left rear tail light just suddenly quit working. The brake light part still works on the tail light. The bulbs are good. I think a bad fuse would have knocked out both sides. Any ideas? 2012 JKU Sahara
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Recheck the fuses. I pinched a trailer wire and shorted out the left turn signal/brake light ONLY. The running lights and the right brake light worked fine. They're mini fuses, and my feeble eyes weren't enough to spot the blown fuse the first go around. Had to pull the spent fuse and examine it up close. Check the owners manual for the schematic, hope this helps!
 

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Are you sure about the rear bulb. The tail light and brake light are on separate filaments within the same bulb. If you already checked that then there's another issue with the running lights. Could be a ground.
 

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Discussion Starter · #6 ·
OK, I just woke up and having my first cup of coffee, the sun is shining, and you guys have given me reason for optimism. Right before this happened I was pulling my utility trailer so now I'm sure I must have blown a fuse. I had no idea the rear tail lights would be on separate fuses. Gonna go check it out after my second cup.
 

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Great thread guys. I discovered that my aftermarket fender flares' marker light fried the fuse which rendered my taillight out. Unfortunately I didn't read this until after I bought a replacement bulb. Oh well. Now I need to replace the market lights with slightly less melted units.
 

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old thread... just help me out too.
2017 rubicon M17 also...

Thanks
 

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For those reading this and have/will/anticipate pulling a trailer, you can blow the tail light fuse even if the trailer does not have a short simply by plugging the trailer light connection up while the vehicle tail lights are on. Nothing worse than plugging the trailer up at night with the vehicle lights on and all the tail lights go dark. Been there and done that years ago. Incandescent lights build up the resistance as they come up to full brilliance. Adding a sudden surge to the circuit can over load it and blow the fuse.

Also, always check the trailer lights after you plug up. Many will turn on the tail lights, see them on the trailer and turn off the lights and turn on the flashers to check the brake light circuit. That is not a full check. Leave the running/park lights on then turn on the flashers and check the trailer to make sure the flasher is brighter than the tail light and doesn't turn it off. If the tail lights on the trailer turn off when the flashers come on, you have a bad trailer ground.
 

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I had a similar issue once and it was a blown fuse. But in my case, there was no trailer involved. The fuse simply blew. I now keep extras around. If a bulb burns out, you should get a message on the DIC, if you have EVIC. Just one more reason to get the Connectivity Group. That's how I found out my rear brake light was burned out.
 
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