Reverse lights stuck on

[climinthewall]

I have a 2010 dodge ram 1500, 5.7 Hemi, and automatic transmission. Also tow package and both 7 pin and 4 pin connections, (Read on to see why I'm including tow info).
About a year ago the reverse lights started occasionally staying on. I would disconnect the battery for a bit then reconnect it and the reverse lights would be off.
It only happened once every few months or so.
Last week they stuck on and despite my leaving the battery disconnected overnight were permanently stuck on so I pulled the bulbs till I could get to troubleshooting.
So, this weekend I did some research. I got under the truck and disconnected the neutral safety switch on the tranny and the reverse lights were still on.
On a hunch I decided to explore the fuse box.
I pulled the tow main fuse and they went out.
With this fuse out I started the truck and put it in reverse. Reverse lights now work properly.
I put the tow main fuse back in, reverse lights stuck on. Leaving the tow main fuse in, one by one I pulled every fuse that was related to tow. Lights still stuck on.
Went over the tow connectors and wiring as well as lights wiring, so far have found no damage or shorts.
There is one section that is a bit squished between the bed and frame. May dig into that when I can, but for now I'll just keep the tow main fuse out unless I need it.
Any ideas about what the problem may be and if I may have missed something would be helpful and thank you in advance.

 

[ConorToot]

Did you ever figure out what caused the tow fuse to cause the reverse lamps to stay on when not in reverse?
I have a 2012 Ram 1500 SLT with a 4.7L flex fuel that is having the same issue you described, but I haven't pulled any fuses yet. I have to renew my state regestration which takes an inspection first. Of course, I was getting a couple other things repaired and was about done when this new caveat started which could take me a while to fix if it persists. I'm fairly certain the selector switch is okay because the reverse camera only comes on when it is indeed in reverse. My reverse video didn't come with the truck, but I added a Tesla style head unit from Phoenix Automotive and an aftermarket camera when I replaced my tailgate that was stolen a year ago. The signal doesn't come from the lights but actually comes from the can-bus signal, which is my indication that the selector switch is working as the video only comes on when it's actually in reverse and not based on the aftermarket shortcut way of wiring it to the reverse lamp signal.
If I can do something as simple as pulling the fuse for the tow module, that will work for now because my trailer that I loved was also stolen when I first moved back to Houston. When coming to Houston, they steal half of your stuff right away. That's why it's called the "Houston Hello".
Hopefully you found a fix since so many replied to your post. Sometimes finding the right and difficult answers is a personal journey that is meant to be traveled intentionally for one person only.

 

[Curmudgeon]

Before even reading both posts above, my immediate reaction was that this is not a bug, it's a feature.

Because it sounds like a really good way to keep tail-gaters off your bumper!

You may now resume your serious and reasonable thread.


EDIT: Hopefully someone with a better answer than mine will chime in, particularly as it doesn't look very promising for the OP to respond...

climinthewall
Junior Member · 50 · From Idaho

Joined Aug 1, 2021

Last seen Aug 2, 2021

 

[Curmudgeon]

So... have you tried pulling the tow fuse? What happens?
Have you checked for squished or otherwise traumatized harness?

I also have to survive the indignity of annual safety and emissions inspections, I feel your pain. Twice before I used a temp work around to survive an inspection mid-winter so I could fix it in better weather.

I'm not a mechanic, just trying to read through and see if I can help. Have you learned anything new since posting? It seems as though you are confident you have ruled out the front end of the truck, maybe it's time to look at the area of the reverse lamps and tailgate?

Also, this is a thread bump. Verbose, yes, but a bump none-the-less.