Gm 2400 engine cranks no start does not smell burnt no was giving code 522780-2 sometimes that says monotroll switches has done that for a while and would test itself and drive. then started this canbuss code started it would not up/ down or drive. Called ALTA he checked wiring messed with connectors and boom has not run since he was stumped. Have wiring schematic if I could email it to you mine is tsbtom at gmail dot com if you want it send me yours.