Alarm set is flashing and that makes it not to star, what do i do please? on 1998 Chrysler Town & Country

Please i have a voyager here (chrysler) there is an indicator on the dash and any time this indicator is flashing the car will not kick,the indicator is alarm set. But there is one funny thing that is happening, when ever i plug in my scanner into the car and left it there it will be working very well, and if scan it there will be no code found, please help.

Asked by for the 1998 Chrysler Town & Country