4l80e tranny issues

[mattpo6]

I have a 1996 3500 6.5 diesel. the other day I changed out the neutral safety switch, cause old 1 was crack by wire harness(kinda corroded). Now with new switch in place, I have NO GEARS at all. (all gears worked before replaced). So then I redid the wire harness to safety switch and transmission cause both were in bad shape. Still NO GEARS.... (ENGINE RUNS & Transmission worked ok b4 putting in new switch) I NEED HELP PLEASE

[rustyk]

Are you saying the engine won't start (the purpose of the neutral safety switch) or that once the engine is running the tranny won't shift?

If the latter, check the two connectors on the driver's side of the tranny. If the engine starts, the neutral switch is not the culprit.

No doubt someone else here will more suggestions.