Just wanted to share an issue that happened to us earlier this year with our Scamp's electric brakes. Our 2012 16-foot Scamp lost its trailer brakes in the middle of a 10-day trip in May, including two scary rainy days (we were really afraid of jack-knifing). Calls to both Scamp and the brake controller's Tech Support groups didn't quite resolve the issue. But: toward the end of the trip, with the help of a friend, we discovered that each wheel's brake unit has a grounding wire that was attached to a little lightweight metal "L" bracket, which in turn had been spot-riveted to the frame and recently broken off. The wires on BOTH sides had broken off, evidently due to severe bumps we took on a bad stretch of Interstate 70. Without the ground wires being connected, the brake controller could not communicate with the brakes and thus thought there was no trailer connected to our vehicle.
For our Scamp these ground wires were red. In other model years, we don't know. Just wanted to post this in case something like this ever happens to you, where your brake controller won't "come on". I was able to very quickly "rig" a temporary fix by connecting the little broken-off brackets to a nearby screw that came down from inside the Scamp through the frame. Back at home, I drilled fresh holes in the frame and screwed those red grounding wires in permanently.
Interesting that your posted this because it relates to a project I am doing this month. First, some background. Yes, the brake magnet gets its negative (ground) connection through the trailer’s frame using those ground lugs you referenced. In fact, in Scamps the ground / negative connection from the tow vehicle typically goes into the camper, then at some point through the floor to a ground lug on the frame. Then the brakes connect to the frame at other locations and all three of these ground lugs are exposed to weather and subject to corrosion and possible damage.
By the way, it does not matter which of the two wires wires from the brake magnets are connected to to the ground lugs because the magnet works either way. So from the brakes you need one wire to ground and one to the blue positive wire (which gets power from the brake controller).
Now about my project. I am replacing my ten inch manually adjusted brakes with self adjusting ones (under $100 for two full assemblies from eTrailer.com). While I am at it I also decided to run the ground wire from the brakes to a more reliable connection. After some thought I decided to also add a 7-gang junction box for the umbilical cord. This will make it easier to put a new cord and plug on when needed, since they do wear out or get damaged / corroded. With the junction box I can easily run an additional 10 gauge wire from the junction box directly to the brakes for the negative / ground connection. That way its straight from the tow vehicle’s ground and there is no worry about a failing connection at the frame, or along the wiring inside the camper before it gets grounded to the frame. This will make for an almost bullet-proof electrical connection for the brakes.
I too have run into electric brake failures over the years. They are a pretty good and reliable system but need checks and maintenance like everything. Another failure mode is after years of traveling down the road the electric puck that actually applies the breaking force to the shoes can wear thru to the coil of wires or the lite springs that hold them in position can rust away and leave you with reduced or non existent brakes. Taking the drums off after a couple years to inspect the brake parts and the bearings and seals can go a long way to keeping them working reliably and properly. the springs and hardware are not expensive and do just wear out. this is the best time to check out the wiring and grounds too. another failure common to these systems is the connectors many trailer builders use is ( Scotch locks ) that are just squeezed on to the wires with pliers but are no protection from weather and may look ok but fail to actually make the connection any more. there is lots of info on-line regarding these brake parts and systems.Or maybe a service stop at our RV center every couple years makes sense.
2019 Scamp 13 standard
You make some good points but also twice say to inspect them "every couple of years." One should note that Dexter and Lippert specify bearing inspection and repack annually. That is when you check the brakes also and the manual details the inspection and minimum shoe wear. Even if the shoes or magnets ("pucks") are not worn down, its good to replace the brakes every 5-6 years, or maybe when you replace tires, because as you mentioned, they tend to get rusty and stick. Now this round I didn't follow that guidance and I just went two years from my last bearing repack ( without all that much travel compared to many others) and from the appearance of the grease I would not think about trying to stretch it out any longer.
On my Scamp there are no scotchlok connectors outside the camper (where they are more prone to corrosion). There was one to split the blue brake positive wire to go to both brakes. It was taped up pretty good but I replaced it anyway a long time ago to prevent problems.
I totally agree with you on the yearly and always mean to but somehow the season sneaks up on me and I do not always get to it. Now Our snowmobile trailer was notorious for salt and snow destroying the wiring. and in-fact I eventually ran the wiring in armored cable to reliably get thru a season.. Yearly adjustment is also critical for best performance. It is easy to blow this off since most axles now have some form of bearing buddy grease fitting. But is still no excuse. Another version of do as It says and not as I do.
2019 Scamp 13 standard