Found I had Broken Brake Wires

[RockyMtnRay]

On the way home from my next to last camping trip (which involved traveling over about 10 miles of fairly potholed, pretty bumpy gravel roads), I made a lunch stop in the rest area at the top of Vail Pass (elevation 10,600). Since I'd been climbing a 7% grade for about 10 miles, I let the engine run for a few minutes to allow it and the the tranny to cool down while I chowed down on my sandwich. Shortly after I stopped, I noticed the display on my Prodigy Brake Controller intermittantly changing from "C" (connected) to "NC" (NOT Connected) This really got my attention as I was going to be making a 6 mile descent of a 7% grade as soon as I left the rest area. So, I reseated the Bargman connector between trailer and Tundra and did a quick visual under the trailer for obvious problems...saw none. Got back in and the Prodigy was now steadily displaying "C" so I proceeded onward...and the display stayed a steady "C" all the way home.

Then on the next camping trip (my most recent one), I found the Prodigy's display was pretty regularly (about every 5 minutes or so) changing from "C" to "NC" but when I tested the brakes (with both the manual override switch and the brake pedal) it seemed I had functional trailer brakes. So I continued the trip and even came back over the top of 11,991 foot high Loveland Pass which has lots of sharp turns and 6% grades. Although the rig handled the return trip just fine...and I seemed to have more than enough braking power...this constant switching between "C" and "NC" was really bothering me.

So today, I jacked up the trailer to adjust the brakes and investigate the wiring. On the street side (driver's side) wheel, I found I had about 2 ohms of resistance for the brake magnet, which is about right. But when I checked the resistance of the wiring going to the curb (passenger) side brake magnet, I discovered infinite resistance...an open circuit! Which meant I was getting braking on only one side of the trailer!! But when I scooted over to the passenger side and checked the wires going into the brake magnet, I found I had the expected 2 ohms...which meant that the brake magnet was fine. This was a great relief as it meant I wouldn't have to pull the wheel and drum to replace anything. So, clearly the problem was somewhere in one (or both) of the wires that run along the axle to connect the two brake magnets. As I started clipping off wire tires I discovered that both of these wires had been severed by blunt trauma...they had been majorly pinched between something and something else and my guess is one of the somethings is the axle's swing arm and the other something was a part of the frame. So I got some 16 GA wiring and replaced both of the wires that tie the two sides of the brake system together. With the brakes freshly adjusted and both of them working, I was impressed with how much braking force I had!!! And the Prodigy's display showed an unwavering "C"!!!

My hunch is that these wires got smooshed at some point when I was bumping up/down the gravel road and if they didn't completely come apart then, they did somewhere later on my trip home. And because the total resistance was now higher, the Prodigy's connection detection circuitry was having a hard time deciding if I did or did not have connected brakes.

Sooooo, if you happen to do any travel over really bumpy roads...or if your brake controller's display starts acting weird, I strongly recommend you get under your trailer and do a very careful inspecton of your wiring to include doing a resistance check with an ohmmeter.

[B_and_D]

Glad you were able to diagnose and fix the problem quickly. I think I will add some sheathed wire and electrical connectors to our supplies in case we might need it.

Have you ever tested your break-away switch? I was thinking that maybe we should test ours. Hopefully it's not like an airbag that you can only use once?

[RockyMtnRay]

Glad you were able to diagnose and fix the problem quickly. I think I will add some sheathed wire and electrical connectors to our supplies in case we might need it.

Yeah, carrying some wire and connectors (as well as the needed wire stripping/crimping tool) is a pretty good idea. And don't forget to bring a little multimeter too...voltage and amperage measurements may be the most commonly done tests but I got to the heart of the problem today in a jiffy by using the ohmmeter function.

I forgot to mention in my post above that I sorta accidentally got a clue that helped speed the diagnosis. On the way back from my last trip, I had to use the brakes fairly heavily to stop at the end of a very long, rather steeply descending off-ramp that in turn was at the end of a steep 2 mile descent on the Interstate. I took that off-ramp to enter a rest area and while I was chowing down my sandwich I decided that a quick check of the trailer's bearings might be in order...I do this at least once a trip to make sure the bearings are not running hot. Well, lo and behold, I found the driver's side bearing was easily 20 to 30 degrees hotter than the curb side bearing...the curb side bearing was just a bit warmer than ambient while the driver's side was pretty uncomfortably warm to touch. Normally the hotter bearing/hub would be the one to cause me concern but I had just made heavy and sustained use of the brakes so I sorta expected both sides to be substantially warmer than ambient. That got me really curious so I did another stop at the next rest area (about 70 miles down the road) and this time I basically coasted to a stop using the tranny for braking...used the wheel brakes just to finally stop from about 20 mph. And this time, both hubs were the same temperature...and both were just a teensy bit warmer than ambient. That's when the lightbulb came on in my head that my TM's curb side brake was most likely inop...and an inop brake could be the cause of the Prodigy's erratic display (until that point I was strongly suspecting the Bargman connnector).

Have you ever tested your break-away switch? I was thinking that maybe we should test ours. Hopefully it's not like an airbag that you can only use once?

:-[ Yeah, inadvertently the night I brought my trailer home. :'( It was after dark and I was trying to use my brand new Powermover to put the trailer in my garage (I have a very steep driveway so a Powermover is an absolute necessity). Because of the darkness I didn't notice the breakaway cable got wrapped around the Powermover's wheel...which shortly caused the cable to be yanked out of the breakaway switch. Sure enough, it did what it was supposed to do...locked the trailer's tires up so tightly the Powermover just was spinning its drive wheel and the trailer wouldn't budge. Took me several minutes to put 2 and 2 togther and get a light to inspect the breakaway switch. Then it took me about 10 minutes of frantic searching before I finally found the blasted breakaway cable wrapped around the Powermover's hub. :P Shoved the breakaway pin back into the switch and then all was well again...finally got the trailer into the garage and then went and had a beer! Although I was afraid I'd ruined the switch...or the brake magnets as they'd had 12 volts applied to them steadily for about 15 minutes, neither seems to have been hurt.

[B_and_D]

Thanks for the info RMR!

You are indeed a TM "God" and I (as well as probably many others) really appreciate your attention and contributions to our TM site.

Very similiar experience to what I had. Came down Wolf Creek Pass and part way down realized that I only had 1 wheel braking on the TM. My controller (Jordan) displays the amps the brakes are drawing, so when the number was suddenly 1/2 of normal, I knew. Got to the bottom and discovered that the wire had corroded inside one on those little blue suitcase connectors and had fallen apart. Curb side brake was useless. Went to the Napa store and bought more connectors. Had it fixed in no time. Amazing stopping power then! Must have been going for some time. Now all the brake connections on the TM are soldered and have heat shrink tubing shrunk on them, plus elec. tape over that.

Also worked for a gentleman who owned a Sunline TT. He had many fruitless visits to the dealer for bad brakes. Finally they found that the wiring had been run inside the hollow axel and had gone bad. New wiring and all was right again. He replaced just about every other componet first, from controller to bargeman connectors.

So it's not just a bumpy road, it could be a lot of things.

Glad your experience turned out OK. Brakes and wiring should be part of all our routine inspections.

[Joe]

Regarding checking the breakaway switch.
Once a year, be sure the battery is good. Then jack up one wheel. Spin it to see that it rotates OK. Then pull the breakaway plug out of the switch. Try to rotate the wheel. It should be locked up. Put the plug back in the breakaway switch and be sure the wheel will rotate. You'll discharge your battery very quickly if you leave the brakes energized.

Joe

[Wingedryder]

RockyMtnRay: Thx for your posting on broken brake wires. As my post states, my 2013 TM is back at the dealer there in the Springs to further ck our brakes & wiring. I've done a cursory ck of wiring underneath, but am giving the dealer another try. Kept a copy of your post though, just in case. I too can image we'd have really good brakes if both wheels were braking! Like you, I deduced that the hotter wheel rim was not the problem, but that the one close to ambient temp after braking down long grades was more the issue. Just knew something wasn't right!


Thanks for the post!
WingedRyder in Littleton

[tentcamper]

Originally Posted by Joe

Regarding checking the breakaway switch.
Once a year, be sure the battery is good. Then jack up one wheel. Spin it to see that it rotates OK. Then pull the breakaway 'plug' out of the switch. Try to rotate the wheel. It should be locked up. Put the 'plug' back in the breakaway switch and be sure the wheel will rotate. You'll discharge your battery very quickly if you leave the brakes energized.

Joe

+2 I do it after I re-pack the bearings or after any time I adjust the brakes. Very simple then.

PS, all my campers the brakes wires have been wire nut connection, which makes it simple to replace or field test the brakes with an ohm meter. I have started replacing the standard wire nuts with the outdoor water resistance/proof wire nuts that have grease in them. I place the connection with the nut up to also act like a hat vs a bowl and collect water.