This part is for a vehicle to vehicle towing kit. What this basically does is, say you have an RV or motor home or pickup truck and youre going to towing another vehicle on all four wheels youre going to need this wiring harness to make the lights on the towed vehicle work with the towing vehicle. Well start by showing you the different components of this kit, its really pretty simple if you break it down. First the connection here is a traditional four pole flat. So you have your four basic signals, your ground, running lights, left turn and right turn. You also have plenty of harness to attach this on the towed vehicle. When you make your connections on the towed vehicle itself, you have to install these diodes here. At the point where you make your connections on your vehicle whether it be your left or right turn or the running light circuit you will have to install these diodes.
To give you a couple of quick notes about these, what happens is they do go in a specific direction in the wiring harness. to keep it simple basically the single prong here is listed as out, that goes onto the taillight itself out to the bulb. Then you get the two inputs here, one of the inputs is going to be the wire you just cut because youre going to splice this in between the two. It does not matter which one, the wire is going to come in one side and out the other. This other pin here is going to provide input from your trailer harness coming from the towing vehicle itself. So for instance you would take your green wire here and run it to the other open end and it will go out and power your taillight being towed down the road by the RV. As you can see theres 4 diodes and theres a reason for that. Theres going to be one for the left and right turns, and both turn signals are going to have there accompanying running lights. So youre going to need a diode for each of the running lights. Now weve opened up a small bag of parts which contains all the spade connectors needed to do the install. Basically what these are, you cut your wire that you need and you splice the wire back and expose about a quarter inch or so of it and these get crimped on. Be sure you have the right tool to do that with because it makes all the difference in the world with a tight connection and loose connection. Once you do that, it just slides onto the diode prong itself. You may also want to invest in some dielectric grease that will protect it and keep things out that would cause corrosion which would eventually cause an open circuit. As one final note you may want to take into account, if your towed vehicle has the same turn signal and brake light bulb, this kit is for you. If you have separate stop lights and turn signals, say for example your turn signals are amber that means theres going to be a different box to achieve that so you have your separate turn signals and stop lights still the same. That covers part # 38955.