John, Glad to hear you got your "new" A/S home safely and are pleased with your purchase. I don't know the reason your trailer brakes locked when backing. Did it occur while backing on ice or slippery surface? Are you sure the trailer brakes were not adjusted overly aggressively? You might try again after adjusting the brake controller in the tow vehicle to reduce trailer braking force. Your brake lock situation when backing has nothing to do with the trucks brakes, ABS or otherwise. The truck's brake controller taps into the stop light circuit of the tow vehicle. When the brake pedal is depressed, the truck stop lights are energized. The same low current electrical signal operates a relay in the brake controller which connects a high current source of 12 volt power to the wires leading back to the trailer brakes. Truck brakes use hydraulic fluid, the trailer uses electric current. Harvey To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
