Broken brake wires

[gsmithii]

Good evening campers. Somebody out there may have encountered this problem and any comments or input are welcome.

This Saturday I found one broken wire at the back of the brake assembly backing plate. The break left a tiny stub of wire visible at the grommet where the brake wires penetrate the backing plate. It appears that a six inch chunk of the rest of the wire to the harness is also missing.

The second brake wire has broken insulation right at the grommet next to the broken wire.

To my eye that indicates mechanical stress on the two wires. I plan to get inside the brake assembly to learn whether there is enough slack in the magnet wires to make one- or two splices per wire to fix the broken wire and the about-to-be-broken wire. The wire clamp on the back of the brake assembly was also open. I'll have to be sure it stays closed after the repair.

Back at the wiring harness is a massive metal swedge on the stub end. Does this seem like somebody tried to make an electrical repair with a hammer?

Comments or cautions are welcome. On first inspection it looks like a fairly simple job (isn't that how it starts?) of repairing the wiring, make it weather-tight and functionally testing the brakes.

Thanks

[TG Twinkie]

If you have access to soldering equipment, you can make new pigtails and solder them to the short wires. Use heat shrink tubing to cover the splices you made.
There is no need to make anything other than the spices weather tight.
When you connect the brake wires to the trailer wiring, route them to prevent any stress by the movement of the suspension.

[idroba]

It is fairly common to have wires break at the magnet end. Water, and especially salty water, gets into the wire where the splice is between the trailer wiring and the brake wiring. It then travels down the wire, turning it into a green mess of corrosion. Then they break.

It can be very hard to find "good copper" to splice onto in these situations. In my opinion, the safety issues involved say to replace the magnets with new ones with good wire, unless you can find a long enough wire of good copper to splice onto.

How do I know? On one 25' AS I owned, 3 of the 4 brakes had broken wires to the magnets. I came stupidly close to rear ending a compact car and pushing him under a tractor trailer in an emergency stop situation on an interstate in North Dakota. Virtually no trailer brakes. The inspection turned up badly corroded wires and no brakes. I now have a tester with an ammeter on it. If I don't read 3 to 3.5 amps for each brake at the trailer connector (6 to 7 amps for each axle) I go for repairs.

[ROBERT CROSS]

IMHO...Don't cut corners with the brakes.
If the insulation is the least bit brittle or the magnet wires are too short to make a good repair I would replace the magnets. Make sure the wires are secured, routed, sealed and long enough to make safe repair.

Good time for a complete brake inspection and wheel pack. Look closely for friction material separation.

Bob

[gsmithii]

Thanks to all for your comments. A summary would be that it's a simple repair but pay attention and do it right - & there's nothing wrong with installing new magnets.

Oh! By the way - I found the broken wires while wrapping-up my first DIY complete annual brake inspection and bearing repack. A good friend and great mechanic offered to teach me how to do the job correctly. By the time I got to the last two wheels I was on my own with help available if requested. It was a mixed business to find the broken wires but the bearing repack was great - no unwanted heat on the hubs after a test drive.

First reaction - "Arrrrggggghhhh. Now the job won't be done today."

Second reaction - "Pretty cool - I wonder if a shop would have found this?"

It looks like the various shops in our area are the usual mixed bag of competence and helpfulness. One offered to sell me a brake assembly or a magnet. Two others gave me chunks of brake wiring harness. My practice is to buy something useful if a shop gives me a small item. A chunk of wiring harness equaled a tube of Sikaflex.