Mercruiser Charging problem

[MarkMuck]

Mercruiser with alpha drive doesn't show a charge . No reading at all. Then after you drive for a while it shows a normal charge. Today we just started it and let it run at the dock. No charge at all. Alternator? Voltage regulator?

 

[littlebookworm]

Is it a single-wire alternator or a multiple-wire one? The single-wire, self-exciting alternators don't relly charge at idle. You can pull it (disconnect the battery first), and bring it to any auto parts store for testing. If it needs replacement, remember to use only a marine alternator, not an automotive one. Otherwise, you could hear and feel a loud 'boom.' Hy

 

[jtybt15]

Could be you need to rev up the engine to get the alt to start charging. Mine is like that. gotta rev to 2500 rpm just for an instant to get it to start charging...getting old, i guess. Just like me. takes a lot of reving to get my motor running.

 

[pocket change]

Make sure the belt is tight enough. If you can turn the alternator pulley by hand the belt is too loose. Don't ask me how I know.