I posted last year about a problem with my brakes. I thought I had the problem solved but apparently not. Sporadically my controller shows the "S.C" readout and my brakes aren't working. I try different things, ie: plug/unplug the main cable...sand the contacts...wiggle the wires right at the brakes..and it will work for a bit, and then same thing, the "S.C" comes on and no brakes. This all happens while driving; sometimes they work, sometimes they don't. So I youtubed how to fix brakes and it shows how important the ground is. But nowhere can I see my brake wiring grounded. They're all connected to a 2-wire cable that goes straight to the main wiring junction box and then a separate positive and negative cable to the batteries. Are there some trailers that DON'T use the frame as the "ground"? I can't seem to find anywhere where the negative is "grounded" to the frame. But I don't know if its a grounding issue or if there is a "short" somewhere. I know the "S.C" reading means "short circuit". I've tried to follow the wiring right from wheel to junction box and other than where it goes through the axel, I can't find any worn wiring jacket. The 7-plug connector that goes into my vehicles plug-in is quite corroded on each contact. I've taken some emery clotch and sanded them, tightened them up and re-plugged, and it will fix it for a bit, but again not permanently. Any RV mechanics on here that can give me some suggestions? I'm tempted to replace absolutely everything right from the wheel brake all the way to a new 7-pin plug. But I'm thinking it's probably just one tiny little spot that's causing the problem. Help!