After installing the baseplate and tow bar setup on our Dodge Durango tow car, we had to figure out the tow lighting. We actually already have the umbilical that connects the wiring from the back of the bus to the front of the car. It was left with the bus by the previous owner. It uses a standard 6-pin round trailer hookup. Unfortunately, we couldn’t really buy a pre-made lighting kit for our car because we had to address an issue. With the Durango, the brake lights will come on anytime the brake pedal is depressed even when the key isn’t in the car. What that means for towing is that with a standard wiring kit, if the turn signals on the bus are on but then the brake pedal in the tow car gets pulled down while towing, the car’s brake lights will override the turn signal coming from the bus. We feel that that is not ideal. There are a few kits available that use the ignition power to turn on a relay on that enables the brake light signal. These kits felt more complex than necessary. We also wanted to be able to charge the battery in the car while towing so the lights don’t drain it down. So, Juan came up with his own way to work around that by creating his own wiring plan and putting together his own kit. It just added a couple of additional steps to the wiring.
Full resolution version of this image is available Here
After having spent two and a half days working on the baseplate and brakes set-up, we had to make sure we got it all done and everything put back together before the day was over because I needed to use the car the rest of the week. Here is where Juan’s DIY lighting plan came into play. He explains it in the video a little better than I can write in words, so you’ll want to watch that if you want the details. The short version is that we have 12V going from the bus to the car battery so that it will charge while towing so the lights don’t drain the battery. Also, to deal with the problem of the car’s brake lights overriding the turn-signals from the bus, we put a relay on the brake lights on each side (normally this would only be a diode). The relay allows the brake lights to work just like regular brake lights when we aren’t towing, but when we are hooked up to the bus the car can’t override the turn signals. Again, Juan does a better job of explaining it in the video.
We got it all done! The lights all work the way they’re supposed to. The car has the baseplate and the brake cables all ready to go. Now, we just wait on getting the bus back from paint to set up the bus side of the towing set-up. If the weather would just cooperate, we should be getting it back very soon! We got a picture this week that shooting has begun! We should be really close to getting it back!!
Watch the video:
Click here If you cannot see the video.
Parts We Used
- 25ft 14 Guage Flat Trailer Light Cable
- CURT 58091 6-Way Round Connector Socket
- Hopkins Towed Vehicle Diodes Kit
- 15amp Blocking Diodes
- Bussmann 30 Amp Heavy Duty Automotive Style Circuit Breaker
- 30/40 Amp Bosch Style Relays
- 100pcs Female Fully Insulated Spade Connectors
- Heat Shrink tubing
- Split Loom Braided Cable Sleeve