Today we are going to be installing the trailer wiring kit part number TL-29BK. Okay the first thing we are going to do before we get started is to go ahead and figure out a way that we want to route our 4-pole wiring harness back to our tail lights. On this particular trailer, we have got a nice long center tube here that is hollow so we are going to route our wires through there. Then we will T it off back towards the back to feed both of our tail lights and our side markers. You will notice that the harness itself is a wishbone type harness which means that it has got a single ground and you have got your running wire and right turn combined and then your running wire and left turn combined. So that you can T them off and split it down each side of the trailer.
Here at the rear of the trailer we have got brackets to mount our tail lights to. And then for our side markers we are going to go a little bit more forward on the trailer. We are just going to put them pretty much equally between the axle and the front of the trailer. Now that we have determined how we want to route our wires and where we are going to mount our lights at, go ahead and start feeding our harness through. I am going to take a steel fish tape, feed it through my center tube here. And with the tape pulled through, we can just take our two ends and tape it to it. And pull through just enough to where we have an even amount with the ground wire. And next we can go ahead and ground our ground wire.
We are just going to go ahead and ground it to the front of the tongue here to a nice, clean, metal surface. If there is some rust or even paint on the trailer, it might be a good idea to go ahead and scrape that down a little bit before we mount our ground wire. I am just going to take a self tapping screw and use that as my grounding point. And since the ring terminal that comes on our ground wire is a little bit too large for that self tapping screw, I am going to go ahead and cut that off and replace it with a smaller one. And then to insure that the wires stay the same length equal with my ground wire, I am just going to pull them tight and just put a little piece of tape there to hold them together. Okay, here with the center of the tube, we can start T-ing off our wires. Again we want the yellow and the brown to go over here on the driver side. Green and brown over to the passenger side. You need to find a way to get the brown wire back up to the front where we are going to mount our side marker light. You can either take an extra piece of brown wire and slice it in to your brown leads and feed it up to here or giving that this is a small trailer and we have plenty of wire, I can actually take and bring it up to here where we are going to mount our light and then we can just kind of continue it back to our tail light. So what I am going to do is take my side marker and basically mount it to the hole that I have here. Again, if you do not have a preexisting hole in the trailer, you can go ahead and drill those out. Go ahead and take and pull the loose end of the wire out.
And the stud that you secure the side marker with is actually the grounding stud as well so it kind of has a dual purpose there. I am going to go ahead and take my lead and kind of secure it to this cross bar here. And then what I will do is open up a section in the wire combination here. We will take a quick splice, the two wires, crimp that down, and our connection is made. From there we can again continue on and feed our wires back to the tail light itself. The installation kit provides these frame clips that we can use on angle iron pieces like this one here to help hold the wire in place. Take the barbed end, that over the metal. I think what I will do is go ahead and run a few clips, bring the wire back to the center, and then continue it back to the tail light there. And then we just want to repeat that procedure for the passenger side side marker as well. Okay, and now that I have got both sets of wires routed back to the middle here, we can continue them back through the rear cross member which is equal with what our tail light brackets are. So at that point we can split them and run them through there respective lights. And then we just want to repeat that procedure for the passenger side. Okay, now we are over here to the rear tail light. You will notice in the back of the tail light here, that there are no wires coming out, but there are four holes at the back. Those holes are what we are going to be using as our connection point to the tail light itself.
Actually there is an existing hole here in the bracket that I am going to feed the wires through. And that is going to allow me to get to the back of tail light assembly. From there we can see we have an extra length of wire, so we can go ahead and cut it down. We are going to take and separate the two wires and we will strip a little of the jacketing back. And you will note on the back of the tail light itself that it is labeled on which side you want to put the wires in. There is two holes available for each wire. So you have the availability to plug two wires in for each function. Over here to the left side you can see we have got the stop and turn which is going to be our yellow wire. Then over here we have got the tail light wire which is brown. With the wiring stripped back we just want to go ahead and it into the back of the tail light into the coinciding color that it was specified. We can take the stripped off end and just push it directly into the hole and there is a little clip inside of there that grabs the wire. You see I cannot pull it back out. There is a little recession here that we can place the wires inside and that will keep them from getting pinched when we it into the bracket itself. We need to make sure that these brackets are mounted directly to the frame work of the trailer other wise you will not get a substantial ground coming through them. And we can just tighten those down. And we just want to do the same thing over here on the passenger side. This will conclude the installation of trailer wiring kit part number TL-29BK.
Questions and Comments about this Video
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
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
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
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
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
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.