The cruise problem could be due to a faulty vehicle speed sensor (VSS) or a faulty brakelight switch (coming on while driving). the airbag light bulb may be burnt out and need replacement or the airbag system may be faulty. Get it checked out ASAP because an airbag problem is a safety issue.
If you want to find a Plymouth specialist, here's our directory link for you:
https://repairpal.com/plymouth-repair-in-fairview-tennessee
RepairPal Certified shops can diagnose and repair your 1998 Plymouth Voyager. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.