Transmision shifting

I have a 93 Dodge Caravan with a 3.3 V6, it will shift fine when cold but as soon as it is warmed up it will not shift out of low gear. After it gets warm as soon as i slow down or stop it shifts to low and won`t shift out

You are going to need to take the car to a trans shop and have the TCM (Transmission computer) scanned. It sounds like its going into limp mode. The problem could be very simple, a matter of just a speed sensor for instance. They will tell you what codes if any that they pull from the computer. Post those codes back here with us. Note: Since this is not an OBD II vehicle, the transmission codes will be 2 digit codes. Post them here for us to see.