On a trip to Cypress-Black Bayou Park out of Bossier LA., We had been on the road about 30 min when my coach started downshifting. I pulled over and the transmission shifted ok and I started traveling again, I had traveled about 5 miles and downed shifted again. I pulled over and checked the fluid leave in the transmission, ok, started up again and drove about 40 miles trouble again, this time an error code appeared,after slowing down I was able to return to speed limit and drive to United Engines in Shreveport. The tech read the Allison code and said I was losing electrical power to the transmission control unit. After 4 HRs of searching and repairing, we found that the mfg. had routed the main start battery cable and a bundle of control wires through a rubber covered bracket at the top of the motor under the bed. The rubber had rubbed off and cut into the wires and had burned some of the wires into. Looked like someone had burned the bundle with a torch. 2002 36' Foretravel with 400 Cummings and 6 speed Allison. 30,000 mi at time of tbl. This fire was only 14" under the bed, lucky we did not have a coach fire, No help from Foretravel. Coach was out of warranty in Jan. and this occurred in May.