1999 Volvo Penta "WT" Models Workshop Manual, Page 32Get this manual
Alternator Belt Adjustment _ 3.0 Litre Models Only]All Models Except 3.0 Litre
CD Crankshaft Pulley Ii Circulating Pump Pulley Alternator Pulley
Belt Tension Check Point
Supply Pump Pulley
Check alternator belt tension midway between the circulating pump pulley and the alternator pulley 1Loosen alternator mounting screws and nuts, and pivot alternator away from engine to increase belt tension2While maintaining pressure on alternator, retighten top screw,
bottom screw and nutRecheck belt tension