I just purchased a 2007 2500 cummins. It does not have any owners manual. I cant figure out how to manually shift it. I can put the truck into drive but when I press the +/- switch on the shifter it does not do anything.
Is the there something wrong or am I too dumb to drive this thing?

 

The +/- isn't a manual shifter - it's the ERS aka electronic range selector.

What it does is limit your upper gear. Select 4 and you'll use gears 1-4, for example.

If I'm in 45-50 mph zones I'll kick it down into 5 so it won't shift into 6th.

 

I was expecting that it would tell me what gear I am in when I hold down the -/+ button. If I press it while I am driving nothing seems to happen. I would think the dash cluster would display a 4 or 5 or what ever gear I just selected?

 

If you are cruising along and hit the - button it should change the D to a 6 or whatever gear you're currently in, then - again it should kick you down a gear and display that gear.

 

Thats what I was thinking. I think I have an issue with the tranny.

 

Sounds like it. Or possibly the switch itself, or the wiring between.

 

PRP,

You can download an owners manual for free from the Dodge website if you click on the link below and put in the year and model of your truck.

http://www.dodge.com/en/owners/manuals/