I recently purchased a new to me 2012 RAM ST 3500 4X4 with the 6.7 H.O. diesel engine. This truck will not be a daily driver and therefore will be parked for days at a time. Since winter is on the way, I'm looking to see if there is a engine heater from the factory on the the truck.

I'll answer some questions first:
This about a 2012 Dodge ST 4X4 crew cab with 6.7 H.O. diesel engine with auto trans.
No, I've never had a diesel.
I am in northern Utah and expect winter temps not lower than -10

 

A heater is standard. A cord however is not. Check under your front bumper for a cord with a cap hanging down. Should be fairly visible once you look underneath. If you don't see the cord you need to buy one. Ebay, Amazon, the Dealer, etc.

Video on the cord:

 

Thanks NV290
I'll give it a look when I get back to the house.