Wiring from RV 7 way to Toad vehicles existing lights?

What I've decided to do is buy a 7way to 4 way cord from the RV to my Toad. Then I will run my 4 way wiring back to my tail lights with Diodes. That way I can use my existing lights on my Cherokee and be done with it. I think this will be the cleanest way as long as I have the wiring connections right in my head.. I don't have a problem wiring something up if I have a wiring diagram but right now it's just kinda in my head how to do it. Shouldn't be to hard I wouldn't think... If any of you have a wiring Diagram that you have already done post it up...

Quote ->My question is can I just mount another 7 way on the front of my Cherokee then run some wire back to my 7 way on the back of my jeep and splice it in? Or is there another way to do it. I don't really want to run portable lights if I don't have to.

Not sure, but probably not. Here is what I did:

I have a truck camper with the truck set up to tow trailers. I wanted to leave the 7 pin RV receptacle on the truck unchanged so I could tow a trailer or my '03 TJ interchangeably.

After a lot of research I ended up with the Roadmaster Invisibrake and decided to buy a pre-made tail light wiring/diode kit. On my jeep it was just a matter of unplugging the connectors to the tail lights and plugging the Roadmaster wiring in series. The RM wiring has Green, Yellow, Brown and ground wires that ran to the front of the Jeep. I mounted a 7 Pin RV receptacle on the front of the Jeep and built a "jumper cable" with a 7 Pin RV Plug on each end to span the tow bar. I just connected the Tail Light Green, Yellow and Brown to the same function contacts through to the truck connector.

My F350 "Towing Package" included a relay to isolate +12V so I ran this through the connector and a 20A fuse to keep the Jeep battery topped up - no diodes necessary.

The Invisibrake was supposed to use the Brown (running lights) wire for power, but I decided to take it directly from the (now charged) Jeep battery through a switch. The Invisibrake is supposed to interpret both Green and Yellow wires hot together as a Brake signal, but I used the Brake signal (typically Blue wire) from the truck connector to activate the brakes.

I called Roadmaster a couple times to ask questions and their tech support was great.

One reply above suggested leaving your key in the Off position to avoid discharging your battery, but if you a flat towing, you obviously need to leave your steering wheel unlocked to let the front wheels track.

Good luck.

So I'm thinking running new bulbs to exisiting rear taillights. I know there is room in my Cherokees taillights for an extra bulb. I've watched a few videos on how do do this but they only show the car side. I'm not sure how to go from 7 way on the RV side down to 4 on the car side.

No. You can not run from the MH 7 pin to the Jeep's 7 pin. There are 3 options.

1. Use removable (magnetic) lights. They can be mounted on the back of the car or on a metal bar in the car's trailer hitch. No diodes needed.

2. Drill a hole in each of the car's tail light fixtures and install a new 1157 bulb/socket. No diodes needed.

3. Connect the wiring to the car's existing tail/brake lights. A diode is needed on each side.

I would not install diodes into the current wiring but instead install a totally separate wiring harness and a set of extra bulbs in the taillights. when you're hooked up to the MH the umbilical will use the separate wiring harness and bulbs. when driving the toad you'll use the mfg wiring harness and bulbs. we did this on our '03 Jeep Wrangler after multiple failures of diodes leaving us with no taillights or brake lights on the Wrangler. we now tow a 2010 Jeep Liberty that uses a separate wiring harness. no problems in the last 5-years.

if you don't need to leave the key in your ignition in the ON:UNLOCKED position you likely won't need a charge line as nothing will be on. our Liberty is towed with the txfr case in neutral, the tranny in park and no key in the ignition (steering wheel does not lock).

Roadmaster has a kit with two diodes in it, E-trailer or Campingworld.com sells them.

http://www.etrailer.com/Accessories-and-Parts/Roadmaster/RM-792.html shows you what to look for.

Basically you cut the wire going to the right taillight bulb, connect the factory wire to one diode input, the bulb to the output. Then connect the right input to the diode's second input terminal. Do the same for the left turn.

For running lights, I tied into the factory wire at the front of my car, and feed the front running lights, and they all light up.

Ground is really simple, you just connect it to any part of the jeep metal framework.

You will have three remaining wires. You can use those for the braking system. In my case, I decided to run a vacuum line from my RV engine to a air hose, to the rear bumper. I connected this to a quick connect, to a vacuum hose to my Ford Edge, and to a second cruise control motor (from a junkyard Nissan car) mounted under my dash, and the cable going to my brake pedal and the floor. So when vacuum is applied to the second CC motor, it pulls the cable, the brake pedal to the floor, and applies the brakes in my car.

I also needed some check valves so that the power brakes are also run by the vacuum line, and a pneumatic valve (from the same junkyard nissan - cars have all kinds of 3 way vacuum valves on them that are energized with 12 volts). So when my brake lights come on (I had to run a wire from under the dash of my 97 Bounder, but if you have a third brake light, it will do the same thing) it energized the 3 way valve, applied vacuum to the brakes and CC motor, and applied them. All for about $35 in junkyard parts.

Good luck,

Fred.

David
go to e-trailer for a light kits. I got one there for my 2014 Honda CRV. Not a problem installing it with the 7 pins

I went from 7 on my MH to 6 on my Jeep. 6 pin is slightly smaller and was easier to mount on the toad. (I also have a Blue Ox base plate) I ran a charge line with diodes. I built my own cable. I ran the wires in clear flexable tubing. Building my own cable I could select the wire size of each wire. I mounted the diodes in a small box near the toad battery.

Building cables. You can buy cable pulling lubricant from electrical supply or hardware store. Use stranded automotive wire. The flexable tubing is also available from the hardware store.

I would add some high current DIODES in the lights lines to prevent the 12VDC lines from the Jeep side getting back to the truck side. Might blow some fuses in the truck side fuse panel

ETRAILER.COM is good source for these items and they also have a great HOW-TO section with videos... I have seen 7-way molded Male-Female Extension cord type items but don't think I have seen a FEMALE to FEMALE molded 7-way cable for sale anywhere. You may have to build that one up if that is what you decide to do.

Roy Ken