Dodge Ram 2500 Tail Light Issue - Full Story + Fix
 

So i joined to post this. I have been racking my brain (existence debatable) trying to figure out why my tail lights (brake light portion) come on and stay on for no apparent reason. Even when keys in my pocket and locked. I think there were a few things that happened at the same time. If one person finds this post and refrains from pulling that last strand of hair out....then we will be "winning!".
Brake lights were staying on, and just coming on at random times during the night. I had heard this may be FCM/ITPM (fusebox) or something. I had replaced that junk a couple of years back. bit it was still in the suspect column. those things are expensive ($500-700). Long story short though....i read thru everything I could find on the net. it was helpful, as it helped me narrow down the problem. I replaced the $22 stop lamp switch above the brake arm and the problem was solved....for a few days. Then the lights came back on and ran down all the batteries. Frustration sets in when one problem causes another.
I went back in the house a few times and counted to 100 sometimes.
It ended up being a damaged/broken third brake lamp bulb. Actually I read somewhere, where this guy just traded out one of his bed illumination bulbs. I did the same and BANG! Lights went off! Merry Christmas 2 me!
Anyway, I wanted to post this, as I would have loved to had this when I was searching. But I have to say that this forum helped in eventually finding the problems. I would say that a lot of people would purchase the fusebox and still be in trouble. that stinks. Any questions...feel free to ask. I will help along with all of the other great folks on here. Happy New Year!!

The bulb in the little brake light on the cab?


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yes...there are (3) bulbs in the housing.. (1) Driverside Bed Illumination, (2) Middle is brake light, and (3) is passenger side Bed Illumination. They keypoint in all of this is stop lamp switch ($22) replacement, and 3rd brake light bulb replacement. That is a couple of cheap tried before going to dealer and/or buying the TPIM (fusebox)

Interesting...........wonder why a light bulb would make things come on and run down the battery?!


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How bright were they when they were on? The truck is wired to always have a little voltage going thru them. Thats how it knows if the bulb is out. I'm wondering of the bad element broke and landed on the other element for the blinker/brake and made them glow a little.

I just changed out the fcm and power control module on the front and same thing, the lights are still on.....grrrr. I will check the third brake light. I changed all the lights to LED, rear, 3rd and bed illumination as well, I think I'll changed everything back to factory and see what happens. This problem is starting to wear my patience really thin......Thanks for your post.

Had the same issue, ended up being the brake controller activating itself. I unplugged it an let it reset and the issue went away...

Brake Light problem!
 

Right rear brake light does not work after replacing bulb. The other two (left & center) and the socket is getting power because the running lights work! Looking for suggestions on what to check/fix!

The wiring for the rear lights runs from the front to the left rear, then the right rear. Between the rear lights, the wiring branches off to the trailer connector. So, if you have power to the left side, your problem will be between the left rear and right rear lights.

Have you removed the connector behind the tail light to check for corrosion and a good connection? Most likely, your problem will be here. Also check the bulb socket for power. The problem may be on the tail light between the connector and the socket. Switch bulbs just to make sure you didn't get a bad bulb.

If that doesn't work, use a test light to see if you're getting power to the right side tail light connector. The brake light wire is white/light green. If no power, test the brake light pin for the brake lights on the trailer connector, if you have one. This will help you narrow down where the wire may be shorting out. You can crawl under the back of the truck and trace the wiring from right to left to check for a damaged wire.

Here's an image of the right rear tail lamp wiring layout. Hope this helps...

https://cimg5.ibsrv.net/gimg/www.die...168d0b2d30.jpg

Thanks!
 

Thanks you! All of that makes sense and i will be checking it out!