i have a 2002 ram 1500 4.7. the issue is its not starting half the time. when it does it idles fine, but when i put it in gear and move it, all the warning lights come on then go out, every couple times that happens with the dash lights, it stalls out. been having a problem starting too, i put the key in and turn it and the only thing that'll come on is the odometer.
ive had the battery and alternator tested, both fine, also just replaced the battery terminals, and checked all the grounds i can find.
the lights on the dash come on driving down the road but it also seems to happen everytime i hit a bump, and it doesnt happen when its just idling.

 

Check the wiring in the engine compartment. I have a 08 ram with the 5.7 liter which was doing the same thing to me. When I would hit a bump, the engine would go into limp mode. After doing some research, I learned that a set of wires that ran along side the engine block had rubbed until they were exposed. When I hit a bump, a wire would ground itself to the engine block and throw a code. After changing the wires, it has not given any trouble. I understand this is different year models and engines, but it may be the same issue. Hope this helps.