C4500 No Forward Motion

[OSCLandscaping]

Have a 2004 GMC C4500, Duramax with Allison Auto tranny. Used the truck 2 weeks ago and it ran great. Tonight I started it up and the truck will move in reverse, but it does act kind of funny. Won't move forward at all. :(

Any ideas would be appreciated.

[The boys]

PRNDL switch

[OSCLandscaping]

PRNDL switch

Do you think it could be frozen, I didn't let the truck run long, we have had a lot of rain and warm temps yesterday, then dropped to below freezing quick.

[Arc Burn]

I know there was an "updated" switch for those,i had to get one,i believe they were a different color,tan maybe,the originals had an issue with moisture.

[Earthscapes]

I agree with them, we replaced the one on the 02' last winter. At first it started slamming into gear & then it just stopped moving.

[OSCLandscaping]

Thanks guys, fixed it. It appears the rear brakes were frozen. Dragged it out into the yard with the loader, had it in neutral and it plowed dirt the whole way. Got it to an area I could back up for a ways, then tried forward again, this time it moved slow and then just started going normal.

Definitely gonna check into the switch though, noticed online they have been an issue.

Thanks for your help. I appreciate it.