On/off only, not to the start position. If there are no codes, it will just say "done".

Does your 2004 Ram have a "chipped" key?
Is the key black (non chipped) or grey (skim key, chipped)?

If it requires a skim key and it loses the programing it will run a short time then die.

The fob is black, pear shaped about two inches long and just over an inch at the widest part, it locks and unlocks the
doors and has the red 'panic' button., the ignition key has a black plastic with the Rams head. The unlock rubber button
came off and I can see part of a green circuit board.

If the key is black, it's not a chipped key aka skim key.

The key fob only operated the keyless entry system in your case.
It has nothing to do with disabling the ignition like a chipped/skim key.

It wouldn't be the reason for not staying running in your case.

Have you been able to check for DTC engine codes with a code scanner/reader?

Update
Cleaned the throttle body and replaced the air temp sender, this solved the problem. Thanks for your help.