Why do my 1994 dodge ram 1500 automatic does not shift into second and third

Check the fluid level
check those with engine warm, idling and gear selector in neutral
check the Throttle Pressure Cable (it is attached to the throttle body and goes down to the trans) - open the throttle body manually all the way (Wide Open Throtle) the TP cable should have all the slack taken up. From your symptoms I would expect to see the cable end disconnected from the throttle body. The plastic end that clips to the throttle body gets crispy and breaks. I have in the past used a couple tiny plastic ty raps to hold it in place on the linkage. If you choose to do that temporary repair - Please carefully inspect the throttle body to make sure the repair doesn't cause the throttle body to bind and not work smoothly. Done improperly the throttle body can stick and you will have a serious problem if that happens.