Intermitent trailer braking problem?

[Customcutter]

I pull a 16' enclosed trailer. I have had intermitent problems when pulling with both a 94 dodge and now my 01 SD. I will be stopping and voltage on the controller will drop below .5 and then suddenly climb to 5 or higher. Both trucks used the same Primus controller by Tekonsha. I just moved the controller when I sold the Dodge. The controller is normally set at about .9 when stopped and if I slide the manual bar over it will climb to about 4.5, average settings I was told by the installer. The problem will go away for weeks at a time and then come back for several days or weeks. I've searched over 1000 messages and it sounds as if it is the ground. I crawled all over the trailer today. I found where the wires had been crushed by the spring leveler, I taped them up but still problems. I then ran an extra ground wire from the 4 pin connector to the trailer ground wire. It is wired with a 7 pin. I checked continuity at every blade splice connector on each brake. All 4 brakes hum when the brakes are applied. Still having issues. It's gotta be either the wiring through the axles to the opposite side or I'm losing ground on the blade connectors. Are they OK or should I replace with twist cap connectors or should I install new crimp connectors and heat shrink them?

It feels like someone slamming into the back of the trailer everytime it happens. Also sometimes when trying to adjust the controller, I can't get the setting over .4 or .5 when stopped or braking. I really hate intermitent problems almost impossible to track down.

Thanks in advance,

[JimTJr]

I would almost feel like it needs total rewireing, you could run new wires thru the axles, but hooking on to the ends, and pulling them thru. That way you would KNOW for sure the wirings integrity is not bad in any spot...
If it still continues then you may have a problem INSIDE one of the drums,, and it may short sometimes in there,,?

[Customcutter]

Is there any polarity to the brakes. I was under the trailer again today and found another problem, a short in the hot wire. I taped everything up. Now there is no slamming (high voltage), I just can't adjust or get any readings over .5 volts on the controller. I guess I'll be redoing the wiring the next chance I get.

[Customcutter]

Finally found the problem. It was in the hot wire inside the front axle. Did the rear first and didn't find anything, so went ahead and got the front and there it was, the insulation was worn through it two places about 2 inches apart. I used someone else's idea and ran new "3 wire extension cord" on the outside of the axles and tie wrapped it securely to the axles. I liked his theory that the wire is now double insulated. Also visible.