Hi,
First off, you are doing well.
I know you are learning. This will always come in handy someday when you get it all sorted out. Keep at it, you can get this.
I can sense your perplexity/bewilderment at chasing your tail on this. I have been there too, mainly chasing rusted grounds, but the feeling is the same.
I can only go by the words you type, and we have a few callout confusions, so let's sort that out first. I am going by what DOT/FMVSS calls each light on the trailer. I can't find the simple Federal 108 lighting chart, but this comes close
Federal Trailer Lighting Specifications | Humphreys Hitch and Trailer Parts
Clearance lights: Clearance lights are on the front wall (amber) and rear wall (red). There are no clearance lights on the long side walls of the camper. On the rear wall, the three red lights in a row at the top of the wall area are clearance lights and indicate that the width of the trailer is greater than 80", and a red light on the top left and right, making it five red lights across the top of the rear wall of the camper
Marker lights: Marker lights are on the side walls of the camper on the left and right sides. Amber is on the front, and red is on the back. There are no marker lights on the front or rear walls of the camper.
Tail lights: These lights on the rear wall of the camper are in the combo housing of the tail light, turn/stop signal housing. The tail light is the lower brightness filament in the dual-element bulb.
The same green wire from the seven-wire truck plug powers all three areas: clearance, marker, and tail lights.
You said this now that we both can see what the lighting words mean.
See the last photo (the wires were switched green to brown). After I attempted to clean my wiring up in the junction box it stopped working again. Left taillight works, right taillight doesn't signal. No clearance lights. Help?
Also where I can I get access to the clearance light wiring? Other than the fuse panel. I'm worried a wire broke off and I'll have to rewire it. I jumped power to the clearance lights and nothing. The fuse is fine.
OK good, you found you had a red and green wire mixup. Now we should have the 7-wire truck plug green, feeding all the green DOT lights on the camper. This pic where the wire were switched
What I think you said, when you switched the brown and green to be correct in the pic above, while the left turn signal still works, that is good, as the red wire is "only" for the left turn/brake high brightness filament. BUT, now the right side signal does not work, and you have no clearance lights. Let's deal with the right side turn signal first. The brown wire "only" is supposed to go to the right side turn signal, the high-brightness filament.
I did not see a clear picture of your right tail/turn signal light. This fuzzy clip from your movie appeared to have the green and brown wires nutted together. Tell us or show us what is happening at this light fixture. The brown wire at that light fixture should be the same seven-wire brown wire and go to the high-brightness filament. Does it?
Regarding the comment about the no clearance lights, I am unsure if you mean only the front and rear wall clearance lights or every clearance, marker, and tail light fed by the green wire. Please explain in more detail, as if all three areas are dead, you are not getting power from the truck 7-wire plug for some reason. If only the front and rear wall clearance lights do not work, but the side marker and tail lights work, that is odd. Again, I'm only saying what you call clearance lights.
Please explain more.
Also, what did you find out at the three fuse block area with the brown-covered thermostat-looking wire stacked under the two green wires? We have never heard the outcome of that.
You asked how to access the clearance lights, as you think a wire broke off. Again, we are back to the definition of clearance lights: only the front and rear wall. Let me explain a little about how Sunline wired the campers.
Since the same seven-wire truck plug green wire powers the front and rear wall clearance lights, the left and right side wall marker lights, and the rear tail lights, they are all, as we call it, parallel wired with both a white ground wire and the green hot wire in a "daisy chain" style of connections. They jump from light fixture to light fixture.
I'm not sure about your 1981 camper, as Sunline may have changed their wiring methods as the years went by, but this is how, in 2003, the rear wall was wired for the green wire that fed all the rear wall clearance lights, the rear tail lights, and the rear right and left wall marker lights. We were restoring this camper, and before we put the siding on, I needed to check that all the lights worked.
In this case, Sunline ran the green, red, brown, and white from the bottom of the camper to the left area of the rear wall. Once inside the rear wall, split up the four wires. Three wires (red, white, green) went to the left tail light fixture. The brown wire by itself went to the right tail fixture area.
At the left tail light fixture, they fed the red wire directly to the high-brightness filament on the left stop/turn signal. The incoming green wire had a 3-wire junction in a wire nut. One green to the left tail light, one green to the left rear marker light, one green to a crossover wire to the right side tail light fixture. The white ground wire-nut joined 3 wires and went to the left rear marker light, the left rear tail light, and to a crossover to the right side tail light fixture.
At the right tail light fixture, the brown wire was fed directly to the high-brightness filament on the right stop/turn signal. The white ground wire-nut joined 3 wires and went to the right rear marker light, the right rear tail light, and up top to the rear wall clearance lights. The green wire fed, again, a 3-wire nut joint, one green to the right tail light, one green to the right rear marker light, and one green up the wall to the top clearance lights.
The top 5 clearance lights jumped from light to light across the top part of the real wall.
The front wall clearance lights and the front left and right side wall marker lights on the longer camper had a separate white and green wire feed from a frame header 7-wire junction box. Since your camper is so short and does not have a frame header junction box, they may have run a green and white wire from the back wall clearance light through the attic to the front wall and jumped from light to light. I don't know, but that is a possible explanation.
The point is that the main wires are buried in the walls. BUT, they create joints at the light fixtures and are stuffed in the wall cavity, so you can pull out the wires and fish out the wire nuts when the fixture is removed. Since all your clearance, side marker, and trail lights were working, some may have been blinking, but they worked. The odds are high that there is a mix-up in the rear wall of the right tail light fixture. Remember, if the ground wire is unhooked or has a bad connection, the green hot wire can be good, but the bulbs will not light.
And, if you have no clearance, marker, or tail lights since you straightened up the junction box wiring, do a voltage check with the truck powering the 7-wire cable. Something may have been disturbed in the process.
1. Does the green wire 7-wire junction box pin have power?
2. Go to the inside of the camper and see if the fuse with the green wire has power, and both sides of the fuse in case of a loose fuse.
3. Go to the back wall with the tail lights covered off and see if you have power at the back wall on the green and white.
You can return to the area where you are losing power and then start the hunt to determine why or if the ground is lost. For chasing grounds, get a long ground jumper wire from a known ground source and touch it at a suspect connection.
I hope this helps, and let us know how it goes.
John
