Define: AC unit? We just need to know a little more about your problem and about exactly what components you are looking to replace.
https://repairpal.com/estimator/saturn/l100
That link is for our Estimator tool - that's a great place to start.
RepairPal Certified shops can diagnose and repair your 2001 Saturn L100. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.