Brake rewiring

Probably loose or dirty connector.
Time to spray some contact cleaner on it.
Bad ground would cause all the messages displayed.

As mentioned above, solder. Western union splice and heat shrink, used this method for 40 years with no failures. Navy trained, control systems on gas turbine power-plants, back when they actually cared more about such things as skills than in being PC.

I had three of my four brakes fail,
* The first was an open wire that ran through the axel.
* The second was a failure of the magnet lead at the splice.
* The third was a dual failure, the magnet lead at the splice and the magnet coil wire wearing through on the magnet face.

When i rewired my brakes each axle i made each axle a home run to the front of the trailer , so if 1 wire had a problem I still had brakes

proxim2020 wrote:
When I rewired my brakes, I ran one main + and - back to a marine grade bus bar. From there I ran a separate + and - to each one of the brakes. I didn't want to run wire back through the axles, so I ran them through some PVC conduit on the outside of the axle.

That's exactly what I did on my previous TT. I fought brake problems for a year when I first got it. Finally I did something similar to Proxim's solution and never had a problem again. I really don't like daisy chains because one problem at the front of the line can cause everything downstream to fail.

KJ

When I rewired my brakes, I ran one main + and - back to a marine grade bus bar. From there I ran a separate + and - to each one of the brakes. I didn't want to run wire back through the axles, so I ran them through some PVC conduit on the outside of the axle. Ring terminals were used for the bus bar connection and all splices were soldered.

I've soldered more connections in my life than I care to think of in all kinds of vibrating and moving environments. Everything from cars, trucks, dirt and street motorcycles, golf carts, trailers etc. Connections have been in protected and exposed environments. I have never had a solder connection that's failed on me. I use the same method each time. A Western Union splice, solder that saturates the entire connection, shrink tubing to protect the connection. I always make sure that the length of the tubing is a minimum of twice the length of the splice and that the tubing closely matches the diameter of the wire.

Adhesive lined shrink tubing is far superior to the regular stuff. As the tubing is heated, the glue inside melts and forms a nice waterproof seal. The tubing permanently attaches to the wire to help further protect and strengthen the connection.

The whole purpose of using stranded wire in vehicles is so the wires can flex with vibrations caused by vehicle movement. Soldering stranded wire creates solid wire and defeats the reason for using stranded wire in the first place. Soldering is fine if the wire is supported in such a way as to prevent any movement. Most vehicle wires are not supported in that way.

An alternative to crimping multiple wires together or soldering is to run an individual wire pair to each brake location. The four individual pairs are then terminated on the tongue on a terminal strip. The terminal strip is installed in an enclosure and the umbilical from truck is led into that enclosure to connect to the brake wires. Terminating using a terminal strip and using this Star layout gets the most power to each brake and makes diagnosis of brake problems easier. Any electrical issue can be diagnosed at the tongue.

I have all of my trailer wire connections on this strip:

I solder then cover with heat shrink if possible, and then cover the entire joint with liquid electrical tape, 2-3 coats of that seals the joint AND provide strain relief for the soldered joint so that it doesn't get stressed. Been doing that for boat/motorcycle/car applications for a long time an never have had a failure.

I've also soldered crimp connectors (after removing plastic) and the same treatment as above for locations where I found that be be easier or wanted an extra bit of safety.

Soldered connections can break with movement. I've soldered trailer wires for years and haven't had a problem either. Probably, the reason my soldered connections don't break is that I support wire runs.