Mystery wires in 88 Bigfoot 17?

[pindraak]

I just put in a new wiring system in my 1988 Bigfoot 17 (used to be gaucho model). Everything that's hooked up seems to work fine, but I have a few mystery wires:

a) Two brown wires that used to go into the old converter/panel box. One goes to the rear, then goes upward, near the bathroom. The other goes all the way to the rear and seems to disappear behind the water tank.

b) Two brown wires coming from the front of the trailer. One goes up and one goes sideways, at the seam. It appears like the sideways wire is the ground for the external light near the lp tanks.

c) Two red wires emerging from behind the bathroom. I think these may be the + and the - for the porchlight, which I removed, but I tore out the interior over a year ago.

I noticed that a brown wire is the ground for the bathroom light, which leads me to speculate that all the browns might be grounds. However, I don't know why two of them would have gone to the old DC panel.

Also, if they are grounds, it leaves only a yellow and orange wire to go to the DC panel from all the previously existing electrical devices and so forth. I guess this would mean most of the existing electrical devices are fed by the white wire harness, and cannot be practically run to the new DC panel and fused, ruining my vision of a well-ordered electrical system.

[john warren]

does everything in your system work, otherwise?
if so,,, "cuff em an stuff em enice" cut them short and tape them up and stuff them away.

[pindraak]

Well, everything seemed to work with the two rear brown wires plugged into the DC panel, and only the stuff I wired up myself worked with them disconnected. However, with everything going, and my converter on "boost" mode, the AC ground wire from the panel to the refrigerator melted, and started a fire!

Luckily I was right there to put it out. I have to replace a few other damaged wires as well as the melted one. I checked the AC, and everything was hooked up properly. The refrigerator was not functioning, but the breaker was on, and I noticed after the fire that its power knob was not quite off. However, I don't think a slightly tweaked frig knob is supposed to cause a fire.

My two hypotheses right now are:

a) it had something to do with the two brown wires. Perhaps they are ground wires, and hooking them up to the DC panel caused some kind of complicated grounding problem.

b) it has something to do with grounding the converter chassis. There is a warning in the manual about not grounding it with the same wire as the "-" out wire. The "-" wire goes to a grounding block with all the other major grounds, then to the frame, via a huge green wire. I hooked the converter chassis ground to one of the huge floor bolts that goes into the frame. It seems like I followed their instructions, but the refrigerator ground wire still melted.

I guess I will make some calls on Monday to Gary at Bigfoot and Progressive Dynamics.

[fusedlight]

One handy tool that I use when tracing wires is this:

Newegg.com - GB Gardner Bender GET-4220K Lan Tracker™ & Tracer

You hook up one end of the wire to the signal injector and then use the receiver to trace the wire. It has, over the years, saved me a LOT of hassle.

[Darwin Maring]

Harbor Freight sells this cable tracker:
Cable Tracker

[fusedlight]

I like the Gardner Bender unit... it comes with special connectors for "solid" connections to the wire being traced...not just a pair of alligator clips.

[pindraak]

Interesting. It seems like most of the wires are bundled up and disappearing into places I wouldn't be able to follow, though. Since I haven't tried a tracker, I'm not sure if
that would matter. Right now, I think all I need to know is what those 4 brown wires are. I'm pretty sure the two reds were for the porch light now.

After thinking about it some more, I am betting the brown wires are grounds. They all seem to run to the extreme corners of the trailer, and are heavier gauge than many of the others, plus I have seen individual lights with a white and brown wire. Also, the refrigerator is the only appliance hooked up to both DC and AC. I think what happened is that I pumped a lot of juice into the 2 DC ground wires, the other 2 were disconnected, so the only way it could find ground was through the frig AC ground wire, which overloaded.

[pindraak]

Problem solved. I decided to go through and figure out what every single wire in the trailer was, if necessary. In the process, I discovered that the existing wiring used black as hot and white as ground. I thought the opposite was universal, so never thought of it. I wired all the existing wires backwards! The DC ground net got pumped full of juice, which could only escape through the fridge's AC ground wires, being the only ac/dc appliance. Once I reversed all the existing wire connections, everything was fine. All the brown wires were positives for lights, pump, etc... After I did that, I also found the lost photos I took of the old panel/converter, which confirmed everything I learned the very hard way.