Originally Posted by RayJr
OMG Why are we making this so complicated? I've been towing a car behind me for years and only had the batt go dead once because the Brake Buddie went nuts and the compressor kept running. As far as tail lights I just install seperate bulbs inside the taillights with wires just like a trailer. That eliminated diodes ??? All the stuff you guys are talking about gave me a headake, ya got to be an electrical engineer. Use some good old GI enginuity. Just my thoughts. Thanks
Some of us are doing this because not all cars can be towed without draining their batteries. With my 2014 Honda CR-V, Honda recommends removing a fuse if the vehicle is going to be towed for more than 8 hours or left connected overnight. I could get down under the dash and squint at the fuse panel with its micro fuses trying to pull one out and re-insert it each time we towed. Or I could wire a "fuse switch" but the micro fuse "port" makes that a bit tight, also. So I wired a charging line because it was easier than the alternatives.
I think this problem is going to get worse since more and more new cars seem to have electronics that are never fully "OFF". For example, with the key in the ACC position for towing my Honda has its Bluetooth system ON whether or not I want it and I sure don't want to disable it and have to re-pair my phone when I want to use it the next time. Similarly, the iPod plugged into the USB port is also powered, etc, etc, and who knows what else is on? IMHO its easier to provide power to the toad than to worry about turning everything off.