@Scout
Does anybody know of an electrical connector that allows the use of the trailer harness connector in the rear bumper to charge a secondary battery in the bed or to hook up an inverter? When I used to drag race, my friend used to use his bumper connector {the 4 flat connector}to charge a second battery in his enclosed trailer to power it for lights and outlets..But I'm not sure how and he's since moved and sold all his racing items..
And, does anyone know of a company that makes/sells items that would bolt to the inside of truck tailgate? I'm referring to the removable panel that gives access to the hand mechanisms. remove that cover and install a new panel altogether..
I'm not aware of any way to charge off of a flat 4 trailer connection as they only have pins for tail/break lights, L/R Turn signals, and Ground. But when I wired my Tacoma for a break controller the 7-way RV-style tow plug includes a pin to charge the batteries on the camp trailer. IIRC It is a 40 Amp connection over a 10 gauge wire. As she sits this line is run straight to the + side of the battery with a corresponding line & pin for Ground. Had I known then what I know now, I would have put a solenoid inline with a switch on the dash so I could turn it off when not in use. I don't see why you could not use this plug for similar charging of on board battery. I did this install myself with some help from the folks at etrailer.com. (fantastic customer service for a discount online shop, Great before and after the sale support. Lots of free install videos on Youtube to boot!) You could use one of these (
https://www.etrailer.com/Wiring/Bargman/WG54006-043.html) to wire up a small "power strip" to charge your accessories. Might be easier to use just the plug and your own 10Ga wires since you are only looking to use a couple of pins (
https://www.etrailer.com/Wiring/Optronics/A7WCB.html).
This Aux line should be acceptable for charging or running a lot of accessories. I think you would be pushing it to try a fridge or winch but just about anything else I can think of should be fair game. If you were looking for either of these I'd look for something specific to the application.
Just make sure your truck is running when in use or you will drain the battery very quickly!
Not sure if you were looking to put the plug in the tailgate or for other accessories. I would shy away from putting the electrical plug in the tailgate as opening and closing the tailgate will take it's toll on the thick wires. I'd opt for in the bed right behind the break lights. Most trucks / vans/ SUVs I've seen have a gap back there to run the stock lights and you can usually fish a wire from just under the bedrail down that chase to the bottom of the vehicle. This is how I got power for my 3rd brake light in my topper.
As for non-electrical tailgate accessories I've seen a bunch of DIY stuff over the years. Coolest I recall was a full size truck where the guy had fabbed a steel molle panel to replace his cover and took the time to get a vacuum formed plastic panel for behind it to keep the dirt and water out of the release mechanism. The commercial the ones I can think of are:
https://adventure-ready.com/store/tailgate-cutting-board-toyota-landcruiser/
https://www.smittybilt.com/product/index/86.htm
Boort