Car Alarms: Montana van, passkey iii, tumbler

Question
have replaced with used ignition switch & tumbler,car not starting.

Answer
Ok, bad news. This truck has the PASSKEY III
system built in to the ignition column.
Yours was rebuilt and now needs GM to reprogram
the PASS III and the keys.

Sorry, no way around that one.

Call service dept. in the morning to discuss
the costs involved.

Sorry about that. Just the messenger here :>/

ALARMTEK
PASSLOCK2.COM