MatrixOnDubs

I installed my mechman alt 5 months ago, between then and now drove the car 3x 20 miles each time. On my way home last time power was reading 11.2 volt, so i tighened the belt thinking it would go back up to it's 14.8 v. But no, car only has 11.2 volts when running and 12.89 when off. Messed with the Adjustable Voltage Boost Module but nothing. Took off postive when running volt's dropped to 6v. Battery is full charged. Any help please!!!