Sounds like bad battery,or bad ground. I had a 1-ton that would start/run,but driving down the road,it would backfire,and the lights would dim,at the same time. Battery to frame ground was good,cab/engine grounds to frame were corroded. If your battery to frame ground is loose/corroded,them nothing works. I cleaned 'em up,tightened them down,and the truck was back to normal. Hope this helps.
Last edited by wetwilly5757; 07/21/2014 6:48 PM.
