USB wall charge plug causes lights to flicker

[Wandering Canuck]

I have a 2021 Alpha Wolf 26RL-L trailer and I replaced the proprietary Bluetooth speaker wall mounted charging port beside the bed with a wall mounted standard USB charge plug (exact same plug used throughout the trailer, ordered from Forest River). The swap was very simple, 12v wiring going to the proprietary charger worked for the USB charge port.

The problem that I am running into is that whenever anything is plugged into the USB charge port (e.g. a smartphone to charge it), the 12v lights in the bedroom flicker between normal brightness and dim. I checked the wiring connections to the USB charger and confirmed that I have a good connection, but the flickering still happens. Does anyone have an idea of what might be causing this, and a suggestion on how to fix it?

Thanks,
Mark

[TacomaJoe]

I had the same thing in my model (see below).It was just the one light above the table that was on the circuit with the usb plate. On a trip, I swapped the light with another spot and sure enough it didn't flicker in the new spot and the new one did. It was intermitent until I realized the USB was doing it. At home I resoldered all the connections and it continued. My fix was putting a switch in the line to the USB (and radio and antenna amp). That stopped the flickering and killed some of my parasitic drain. Whatever electronics in the USB plate that turns 12V into 5V seems to affect the electronics in the LED light. Only affected the one light on that circuit so whatever is going on wouldn't travel back to the panel and out the other circuits.

[Wandering Canuck]

Thanks TacomaJoe! Did you install the switch inline with the 12v power going to the USB plate? When you turn the switch on and plug in a device to charge, do your lights still flicker? I am trying to figure out how the switch would fix this problem. I suspect your are right that the USB plate electronics are doing something strange, but I am a bit baffled why I have not seen this problem with any of the other USB plates in my trailer (there are 6 other USB charging plates in the trailer that work fine).

Originally Posted by TacomaJoe

I had the same thing in my model (see below).It was just the one light above the table that was on the circuit with the usb plate. On a trip, I swapped the light with another spot and sure enough it didn't flicker in the new spot and the new one did. It was intermitent until I realized the USB was doing it. At home I resoldered all the connections and it continued. My fix was putting a switch in the line to the USB (and radio and antenna amp). That stopped the flickering and killed some of my parasitic drain. Whatever electronics in the USB plate that turns 12V into 5V seems to affect the electronics in the LED light. Only affected the one light on that circuit so whatever is going on wouldn't travel back to the panel and out the other circuits.

[TacomaJoe]

The problem is still there if I turn on the switch. The switch was part of a project when I removed the antenna on the roof to make room for another solar panel, saw the wiring for the antenna amp and decided to isolate all of it. I use a power strip by the table with a couple of cube chargers now. Looping the wire through a ferite core might clean it up.

[D W]

Chalk it up to cheap chinese electronics. My bride ordered a 2 pack of USB outlets from Amazon. I installed one in the kitchen per her wishes. Guess what? It made the LED under cabinet lights flicker. Sent them back to Amazon, and installed a Leviton USB outlet from Home Depot. Problem solved. One Leviton outlet was $7 more than Amazon 2 pack, but you get what you pay for!

[Wandering Canuck]

Thanks DW. I will follow up with Forest River and see if it might be a defective USB wall mount. The other thing that I was going to try is to swap it out for another USB mount in the trailer & see if the problem follows the outlet.

Originally Posted by D W

Chalk it up to cheap chinese electronics. My bride ordered a 2 pack of USB outlets from Amazon. I installed one in the kitchen per her wishes. Guess what? It made the LED under cabinet lights flicker. Sent them back to Amazon, and installed a Leviton USB outlet from Home Depot. Problem solved. One Leviton outlet was $7 more than Amazon 2 pack, but you get what you pay for!