Backup Flood Light, 5.0 TA

[David W]

New 5.0 TA, interested in connecting a LED flood light for backing up at night. When taking delivery today, we chatted about the junction box on the structure holding the kingpin. I believe this is the junction box where the seven pin harness from the tow vehicle connects to the seven pin harness from the trailer. Any thoughts about using the yellow (back up) line at the junction box for the flood light? Maybe put a single throw, single pole switch and leave in the off position during daylight?

[C&G in FL]

Originally Posted by David W

New 5.0 TA, interested in connecting a LED flood light for backing up at night. When taking delivery today, we chatted about the junction box on the structure holding the kingpin. I believe this is the junction box where the seven pin harness from the tow vehicle connects to the seven pin harness from the trailer. Any thoughts about using the yellow (back up) line at the junction box for the flood light? Maybe put a single throw, single pole switch and leave in the off position during daylight?

Years ago (2015), I had Reace run the center conductor on the 7-pin, normally used for backup lights, to the rear cabinet over the dinette to connect to a rear view camera that was mounted to the underside of the cabinet. I did some wiring to allow me to switch the camera on and off from the driver’s seat. Due to IR creating glare on the window glass, it is useless at night. I have a magnetic mounted “floodlight” that I attach to the rear bumper and plug it into an exterior 12vdc outlet for backing at night. Some people use the center conductor to power the emergency brakes (breakaway switch) which is wired to the 12 vdc charging line from the vehicle (bidirectional flow) and ultimately to the trailer battery when they install a DC to DC charger, as the DC to DC charger prevents reverse flow and in a breakaway situation the trailer brakes would NOT be active. Some owners have run a separate line and connector for DC to DC chargers when they have power hungry lithium batteries (which draw more amps due to faster charging rates) as most tow vehicles do not have adequate gauge wire in the 12 vdc aux line, also referred to as the charging line in the 7-pin setup.
I would personally suggest you use a magnetic mount and exterior 12 vdc outlet or wire a flood light with a waterproof switch into the trailer’s running lights and save the center conductor of the 7-pin for some other (perhaps more important) purpose that may crop up in the future, rather than a very limited purpose such as night time backing. And if you are like most owners, other purposes will arise in the future. You do, however, have to make whatever choice you perceive as best for you.

[SRS]

Originally Posted by David W

New 5.0 TA, interested in connecting a LED flood light for backing up at night. When taking delivery today, we chatted about the junction box on the structure holding the kingpin. I believe this is the junction box where the seven pin harness from the tow vehicle connects to the seven pin harness from the trailer. Any thoughts about using the yellow (back up) line at the junction box for the flood light? Maybe put a single throw, single pole switch and leave in the off position during daylight?

Late last year I installed a backup light on the rear bumper of my trailer. I used the yellow pin in the pinbox, which only gets power when when the transmission is in reverse, to connect the backup light. I have ETI's full lithium package and a DC-DC charger. Attached is a photo of my pinbox before I installed the backup light. As you can see, the only wire connected to that pin is one coming from the 7 pin trailer plug and wire. Depending on how bright the light is you may want to install a separate switch. I wanted a backup light because many of the gas stations I fueled at were crowded enough that I often had to backup to get out. I wanted other drivers that might come up behind me to know what my intentions were in case they couldn't see the backup lights on my truck.

[Centex]

Originally Posted by David W

... Any thoughts about using the yellow (back up) line at the junction box for the flood light? Maybe put a single throw, single pole switch and leave in the off position during daylight?

Just FYI / FWIW (noting I am a 'solo traveler' in my 5.0TA, without a companion to serve as 'spotter') ...

• I ran a wire from the yellow stud in the junction box to the rear of the trailer (wish I'd thought to ask ETI to do that!). As expected, it works just fine to activate 'backup lights' when the truck gearshift is in reverse.
• I also installed upgraded RV LED taillights with larger than OE red Stop/Tail/Turn arrays and integral white backup lights.
• My trailer backup cam is mounted on the exterior of the trailer above the rear window and does not have any built-in IR lighting or specific 'low-light capability'.
• Of course, day or night, I always 'get out and look' before backing my trailer into a parking spot and note the presence of any obstruction I might get close to, intentionally or otherwise (e.g. a row of posts defining the limits of the parking space).
• In dark the white segment of the taillights and that cam serve to provide an adequately illuminated view of the area within ~10ft of my trailer's rear bumper, certainly adequate to guide me as I slowly approach an obstacle. The view is similar to that provided by my truck's OE backup cam and backup lights at night.

I did not install any separate switch for the backup lights; when reversing in daylight they just serve the function of 'warning' (but not 'blinding') any person / vehicle behind me like my truck's backup lights do when not towing. Unless it is 'blinding' it would seem you could do the same with your 'floodlight'.

IMO / IME it doesn't take a lot of light / light-spread to provide adequate backing illumination; please consider that too bright / too 'broad' lighting of that sort may disturb other campers in the vicinity at night.