Chrysler Repair: main key missing, plymouth grand voyager, grand voyager

Question
My grandfather bought a nice running 1998 Plymouth Grand Voyager for the family boys to fix for our mother. However, the main key is missing and we were only provided with the Valet Key. Everytime the door is opened the alarm goes off. Now do they boys need to change the entire ignition lock cylinder and buy new keys, or can we call a lock smith have him take out the cylinder and cut a main key. My grandfather named the van Screamer! Can you help us with screamer? Thanks.

Answer
The valet key should work in the ignition cylinder. If it does not then you'll have to call either a dealership or locksmith to get the cylinder out and cut new keys. That the alarm system is activating gives me pause though. If the van came with a factory alarm system you'll have no choice but to take it to a dealer. The keys are special and would need to be programmed in order to deactivate the alarm.