Most likely the IAC. The same thing happened to me a few weeks ago. Read my post. https://dodgeforum.com/m_1230831/tm.htm
To replace the iac you'll need a torx set someTB cleaner and like 30mins. Remove the airbox. Behind the TB there's what looks to be a sensor. That's your IAC. Unplug the wire on the back of it. There are 2 torx screws on either side of the unit. Remove those and pull the IAC motor out. Don't just pull the IAC, clean the shaft it was in as well or you'll just mess up the new one. Then just put everthing back together. It's a very easy process.

 

i have a 2000 ram and i had that same problem about 2 years ago. after wasting money on a new iac/ throttle position sensor i did some research and found out that rams have something called an ASD relay which means automatic shutdown relay and when it goes bad it'll do just that. i'm not sure about the 97s but on my truck all the relays in the fusebox in the engine are the same so if yours are too then you should take your fog light or horn relay and swap it for your ASD relay, if it runs ok after that then you should run down to napa with 8 bucks and get a new relay.i keep a spare in my truck incase that happens again.