So, I just received the tail light converter box needed to install the 4 pin trailer light plug. Looking at it, I noticed it needs constant 12v from the vehicle to operate. I will be installing the box behind one of the plastic panels in the rear of the vehicle. Does anyone know if there is constant or keyed 12v at the rear of the vehicle, or will I need to run a new circuit?

1984 DL Wagon

Thanks!!!

 

It's been a while, but I installed one of these in both my 245 and my 740. They were the variety sold by U-Haul. I don't remember constant 12V being a requirement; I certainly did not run a feed wire forward. I can't imagine why it would be needed...are you sure you read the schematics right?

 

the trailer light converters I've used all needed power, on one car, I tapped the power I'd already run for the stereo amp in the trunk

I generally run that power all the way from the positive terminal, which on a 240 is under the hood, but on a 7/9 is under the dash on the drivers side. I run it down the left door jams, just under the edge of the carpet, and between the base of the back seat and the left side of the car, then into the trunk area, under the floor decks. You want to use unswitched power so the brake lights work even if the car is off, but have a fuse in that
circuit just past where its powered from.