RobG

Okay, here's the latest update. I spent several hours yesterday afternoon digging around and testing.

I pulled some of the underbelly cover back to find the actual wire. Much to my surprise (why I'm surprised, I don't actually know) but there is NO INSULATION UNDER THERE -- THANKS KEYSTONE. Anyway...

So... found the actual wire. It's a black and white wire encased in a red sleeve. I traced it from the axles all the way forward to the generator compartment where it disappeared into the 5th wheel overhang area and came out at the junction box.

First up, for one reason or another, the black wire (which is actually positive -- thanks again Keystone) wasn't connected at all. It looked cut. The white wire was connected to ground. So I connected the black wire to the wire I knew was the brake wire from the plug. The brake controller shows "SH" for Short.

Next up, I decided to cut the wire to the axles... I did that then got out my spare batter. I heard the CLICK of the brakes engaging and disengaging as I applied and removed power. So at least that much is good.

Next, I tried bypassing the hot lead from the junction box with a long piece of wire I recently bought. I hooked it to the proper wire on the plug and then to the hot wire going back to the axles. Same result... "SH"

At that point it was getting late and starting to rain, so I called it a day.

I see two possibilities...

- Something in the plug-to-junction box is messed up
- Something is still wrong at the brakes themselves; i.e. if they respond fine to 12v, they could still be doing something that the controller doesn't like.

Any ideas?

Rob

PS: When I tested continuity between those two wires earlier, I didn't mean the wires going TO the brakes; rather the wires that ran up into the trailer and to the junction box. So actually, maybe this validates my suspicion that something in the plug-to-junction box has shorted. Hmm...

Busboy

First, if the brakes responded to 12 volts them I'm pretty sure the brakes are good.
Second, I did think you meant the 2 wires going TO the brakes, you should NOT have continuity between the brake power and the ground wire with all the brakes disconnected, they are shorted together.
Third, I don't remember if you have taken apart the trailer connector, I always "tin" the ends of the wires before connecting them up, that way they can't come apart and short to each other in the plug but most people don't do that.
Fourthly, my daughter bought a used 5ver last year and the brakes didn't work, I found the wire cut through and shorted to the frame where it passed between the frame and the floor. I rerouted the wire and spliced it back together and all was good.
Fifth, failing all this I would just get some shielded 2 wire and run a fresh 2 wires to the brakes. Good luck.

RobG

Thanks!

I think I figured it out. Somewhere in the wiring between the plug at the truck and the junction box, we've got a short between the brakes and the ground wire. The plug itself is molded and can't be opened, so I decided to just cut it off. I then tested the plug for continuity between brake and ground and there was none. So then I tested the wire itself (with the line between the trailer and brake wire at the junction box disconnected) and got continuity. Bingo. It's the cable itself.

So... ordered a new cable and junction box on Amazon, due here Monday. The Keystone-provided box is, of course, a nasty jumbled mess so I'll replace it with this nice one.

I'll report back when that's all done.

Thanks everybody!

Rob

mini14

If it were me I would cut all the wires and re wire. Run each ground from the magnet to a chassis ground separately. Have a left side and right side power wire go directly to junction box. Solder all connections. I've done this a few times. Actually takes less time then looking for were the fault is

KATOOM

RobG, I'm glad to hear you're figuring it out. And yes, you're also seeing what everyone one means by how simple the brakes work but yet can be so easily botched up by some terrible factory installation job.
And.....I laughed at you finding out the undercarriage isnt insulated. Yeah, the "arctic" packages they sell people are usually just a covered underbelly which keeps the cool wind from reaching the exposed tanks and plumbing. Well in saying that, I've seen some packages which have small heater units (or tie into the HVAC) thats supposed to keep the underbelly area warm enough to prevent freezing.

If they actually insulated them with some fiberglass then that would be pretty cool. But on a positive note, the material does allow the wind to flow under the trailer smoother without bouncing around the plumbing and tanks and wires, which supposedly helps with fuel mileage.
All in all, RV trailers (well most RV stuff, for that matter) are just cheaply built units which go through fast assembly lines. Its kinda amazing they can get away with such high retail costs.

RobG

Yeah once I get where I'm going and settled (all I'll say for now is I'm heading south.. the hell out of Oregon!) and rent a house with a big yard, I'm going to be doing a LOT of work on this trailer. All that underbelly covering is coming off and I'll be doing a more thorough job of making the thing winter-proof before putting it all back together with real insulation. I will also cover the garage area, which they didn't do from the factory.

Thanks to everybody for the help! Like I said, I'll post more when I get the new wiring harness installed.

Rob

RobG

Sigh. I'm ready to burn down this f'ing trailer.

I put the new junction box on and hooked it all up. Guess what? Continuity. To skip a long story, I ended up cutting the wires to each of the three axles. Only with all three axles disconnected do I NOT have continuity.

If I reconnect each axle individually, no matter which way I connect the wires, I have continuity. So my only conclusion is that each axle is shorting out.

What the hell is going on here??? Do I really have six bad brakes? I'm not sure what to do next. I don't look forward to having to pull each of the six wheels and tear into the brakes, only to find out they're all fine or something.

RobG

Okay, they're fixed. Finally.

Here's the thing. Continuity is irrelevant as long as the wiring itself is intact. Once I replaced the junction box and wire to the truck, which eliminated the short, it still showed continuity. That's because, as I read elsewhere, it doesn't matter. So I went to a lot of testing trouble for nothing. But now all three axles are connected and the brake controller is showing an active connection.

Phew. This is probably the last sunny day we'll have before I leave town, so I'm glad it's done.

KATOOM

Just imagine how much you've learned.....