

Today on This Old Trailer we are going to replace the wiring on this trailer. Right now, this trailer has a 5 pull socket here and the owner uses a patch cord in between here and his tow vehicle. What we are going to do is remove all this and add a 7-way cable that leads right to his tow vehicle. We will be using part number H20046. We will unbolt the connector here. Then we will go ahead and untape it and undo the screw right here, it should release the inside part where the pins are and the wires are connected. Tale that, push everything out. Simply disconnect our wires. 1:04
Now we have our bare wires, we will go over the code real fast. White is going to be your ground wire. Blue is going to go to the lock-out switch on the hydraulic brake controller. Yellow is going to be left turn. Green is going to be right turn. Brown is going to be your running lights. Now we are going to take our wire harness and thread it through the front here, try to guide it back to the hole where the socket was. We will take it and pull it on out, it is an 8 foot length, so we really do not need all of that. We will pull out some, and hook up our other end of the 7-pole to the tow vehicle and see how much slack we need. 1:53
We will use some tin snips to cut off our excess length. Cut the sheath so we can get to the wires. No we will strip back the wires on the ones we are going to use. We will use this green wire, red wire, yellow wire, brown wire, and white. We will not be using the black wire or blue wire since there are only 5 wires being used on the trailer. It is pretty tempting to match up the wires color for color, but you really can not do that because the 7-pole connector actually has a separate wiring code. In this case, green is going to be our running light circuit on the 7-pole, and on our trailer it is going to be brown. So we have to make the conversion. We will go ahead and start off by making our connections with that. To make our connections we will be using little connections called butt connectors. The wires butt together and we crimp them in place. Our next wire on the 7-pole is brown which is our right turn signal, and is going to hook up to green on our trailer, which is right turn. Red on our 7-pole connector is going to be our left turn signal, and the left turn on our trailer is going to be yellow. Next, we will work on our white wire that is the ground on the 7-pole, that will actually match up to our trailer so we will be doing white to white. Okay, our last wire is yellow on our 7-way connector which is the reverse lights and then on our boat trailer it is special so it is going to be the blue wire. 4:11
Now what we are going to do is tape this all together and seal it up for good. Tuck everything back in. We are going to wrap a zip tie around it which will help hold it in place. That will keep it extra secure. We will just leave this open, and now we are set. With that, that will finish our install of our 7-pole connector, part number H20046 on This Old Trailer.
This Old Trailer: Wiring Trailer Tail Lights

In this edition of “This Old Trailer” we are going to wire up the lights on this trailer. Previously we had hooked up electric brakes and you can see, right now we have the junction box installed on there and we have wires ran for electric brakes. We have nothing for the actual tail lights themselves. That is what we are going to start on today. :30
This Old Trailer: Finding and Fixing a Broken Wire Part 2

Next we are going to go to less obvious stuff. Say for instance you have got your ground wire hooked back up to the frame and weird stuff happening out back. We will have to dig into the wire itself a little bit. In this case basically you want to check your wiring connection. You have a wiring connection right here that could be a potential problem right there. Chances are whatever fitting you used to put the wiring together might come loose. And also we have something kind of obvious too. The wire here has a little bit of road rash on it. You can see the bare wires on the inside. Even though it may still be making contact eventually this wire here will corrode up inside there and it will just lose contact so we are basically going to have a broken wire eventually. Lets go ahead and take this apart here we will see what we have got on the inside. 01:14
This Old Trailer: Troubleshooting the Full Ground Wire

We have demonstrated all of these fixes checking the ground on the trailer. The trailer itself is actually used as a ground obviously. Now there is some cases where you boat trailer guys and some small utility trailers out there, the ground is actually carried in a separate wire that lowers the trailer frame completely. The same tricks apply to check and make sure your light is working. Again the connection to the light could be bad or it could be actually a smashed wire underneath the frame of the trailer or also up front where you have got a little bit of road rash dragging the ground. We will go ahead and show you next an example of that type of wiring on a different trailer. 01:04
This Old Trailer: Troubleshooting the Ground Wire

The first thing you want to do when you first start working on electrical problems is you want to divide and conquer. You have two parts here, the truck and the trailer. You want to verify which one actually has the problem. Chances are it is going to be on the trailer, but then again you still want to check the truck too. So use a separate light tester, hook a ground not to the frame but to the 4-pull ground itself because this is what is going to carry the ground to the trailer. :52
This Old Trailer: Finding and Fixing Wiring Shorts Part 2

Now we will move on to another circuit. In this case it will be the right turn circuit. And we will just check the signal on that. On the right turn signal here again, the same principle applies. Start from the front and work you way back. What happens a lot is that on some of these lights here where the wire gets ran in behind it, there is a channel that these wires fit into. However a lot of times, even on brand new trailers. This wire actually does not fit in the channel, they miss when they put it together. The wire gets smashed between the light and the frame of the trailer. Eventually they wear down to a minuscule spec of wire that is visible but it will cause a short and all kinds of headaches.