12 volt fuse keeps blowing

[sammorter]

Hello,

We've had our 2025 Avenue 33RKS for about six months, and we've gone on several trips in it without any problems. It is currently parked on our property and it's connected to 120v house power via extension cord. Recently, out of nowhere, the 12 volt fuse for Light Zone 1 blew. I replaced it, and it blew again. This fuse controls the overhead lights in the bedroom (the switch is on the dresser), the bedroom closet, the lights above slide out 2 (dining area and recliners), and the lights under the cabinet (where the fuse panel is). I would prefer to not take the unit all the way down to the dealer, and hope I can troubleshoot this issue before it comes to that.

So, I contacted Alliance Service department, and they suggested that I swap out switches to see if one of them could be causing the issue. I ordered a new switch from Amazon and started with the bedroom switch. Nothing - it blew the fuse immediately. Next, I swapped out the switch above the booth in slide out 2, and it also immediately blew the fuse. Finally, I swapped out the switch above the recliners in slide out 2, and it worked! The fuse didn't blow, and all of the other lights on this circuit worked.

A couple hours later, I went out to the RV to close it up for the night, and the fuse was blown. Does anyone have any idea what is causing this fuse to keep blowing?

 

[BryanValRox]

Hello,

We've had our 2025 Avenue 33RKS for about six months, and we've gone on several trips in it without any problems. It is currently parked on our property and it's connected to 120v house power via extension cord. Recently, out of nowhere, the 12 volt fuse for Light Zone 1 blew. I replaced it, and it blew again. This fuse controls the overhead lights in the bedroom (the switch is on the dresser), the bedroom closet, the lights above slide out 2 (dining area and recliners), and the lights under the cabinet (where the fuse panel is). I would prefer to not take the unit all the way down to the dealer, and hope I can troubleshoot this issue before it comes to that.

So, I contacted Alliance Service department, and they suggested that I swap out switches to see if one of them could be causing the issue. I ordered a new switch from Amazon and started with the bedroom switch. Nothing - it blew the fuse immediately. Next, I swapped out the switch above the booth in slide out 2, and it also immediately blew the fuse. Finally, I swapped out the switch above the recliners in slide out 2, and it worked! The fuse didn't blow, and all of the other lights on this circuit worked.

A couple hours later, I went out to the RV to close it up for the night, and the fuse was blown. Does anyone have any idea what is causing this fuse to keep blowing?

So, you likely know fuses are designed to blow when too much current is flowing thru them. A normal switch would normally not cause this to happen.
My guess based on your description is that you have a rubbed wire causing a short circuit somewhere in the area of the last switch you swapped out.
The clue is swapping the switch, once you disturbed (moved)the wires in the process of changing the switch, things seem to work for a while.
I would trace that wiring and looked for rubbed areas that could be shorting out. I would pay particular attention in the area under the slide, where the wiring must move in and out with the slide movement.

 

[Dandi Lamb]

I had an issue with the wiring below one of my slide outs, was causing the fuse to blow. I found the bad wire, and cut off the exposed section and taped it up with electrical tape so the fuse would stop blowing. Temporary fix, but I don't really use the lights in that particular slide.

 

[Midnight Rider]

I had an issue with the wiring below one of my slide outs, was causing the fuse to blow. I found the bad wire, and cut off the exposed section and taped it up with electrical tape so the fuse would stop blowing. Temporary fix, but I don't really use the lights in that particular slide.

Rambo Move!
Nice Work!

 

[Dadmck]

I had a short in my Delta 321BH, which was causing our fuse to blow. In our unit, Alliance uses wire connectors which makes it easy to remove wires the wires for testing. I pulled my fuse box out in found the fuse that was blowing went to 4 branches. I tested each one for continuity to ground, and found that (to my surprise) two branches and shorts. One was easy to find… a wire that had rubbed bare against a metal bracket in the rear AC. The other was harder to find, but I found which device (CO detector, kitchen exhaust, bathroom fan, thermostats) was closest to the fuse box. I went to each one and and disconnected the rest of the circuit and retested for continuity. I was able to isolate the bathroom fan and remove it from the circuit temporarily. Everything else works, and I’ll have the dealer address the fan when I take it in for service late in the fall. Hopefully this helps in some way. I appreciated the color coded wiring and the connectors, which helped a ton.