Windshield wippers wont stop

Hi Robert, were the wipers behaving like that before you replaced the multi function switch? If so, it's the wiper motor. There's a relay inside of the motor that, when you turn off the wiper switch, is deenergized and allows the wipers to park. Try tapping on the wiper motor and see if the wipers will park then. If so, that's definitely what's going on. These relays on GMs tend to stick when they get older. The relay is not replaceable by itself. Hope that helps! Jim

Was this a pre existing problem? And the reason for combination switch replacement? New doesnt always mean its good.

Probably the module in the motor , Remove the entire linkage to get the motor off instead of while it's in the vehicle . The one I bought from NIPA lasted a year , buy OEM parts from AC delco ,