RepairPal Certified shops can diagnose and repair your 2003 Buick Regal. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
With door open - closely observe dome light as you manipulate seat switch - - do you see the dome light dim at all .. IF so - power is being sent to the seat - this problem is within the power seat mechanism - under the seat.
Good luck!
IF dome light does NOT dim at all - problem is within the ‘power supply’ circuits.