2001 HD Trans Issue
 

Hey guys, I live in WV and we had lots of snow this winter. I took my truck (2001 HD, 8.1 w/Allison) to the dump for the first drive since the deep snow we had. The only trans indicator light on the instrument panel that works is reverse. It has plenty of power in reverse. No indicator light for Park or Drive. Truck seems to be struggling to go when in drive. It's also shifting much harder than usual from gear to gear. I'm guessing that I'm having an issue when a sensor somewhere underneath because of the snow, but not sure where to look. Trans fluid is full and looks good. Anybody have any ideas where to start? Thanks in advance.

Update-Took the truck for a drive. Feels like it's stuck in 2nd, won't shift once in drive. Reverse, Neutral, 3, & 1 all have indicator, Park, Drive, and 2 do not. Any ideas?

First, check ALL connectors on the tranny....unplug them all and plug them back in. You will probably find a loose or corroded conector.

you can also have a bad range switch on the trans.