Today we are looking at the Optronics 6-1/2 inches Oval Trailer Stop, Turn and Tail Light, part number ST70RB. This light has a red oblong light that serves as three functions, stop, turn and tail light. It has a sealed waterproof housing and lens unit. It comes with a heavy duty long life bulb. It accepts the industry standard 3 prong plug which is sold separately.
It flush mounts with a mounting grommet and plug. Weve already connected a three prong plug so we can show you what it looks like when we attach a power supply. Red wire will be our turn and brake signal, white wire will be our ground, and the black wire will be our tail light. Theres our tail light, and our turn, or brake signal. Now were going to turn off the overhead light so you can see what it looks like when it is dark. Theres our tail light, and our turn or brake signal. And there you have it for the Optronics 6-1/2 inches Oval Trailer Stop, Turn and Tail Light, part number ST70RB.
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.