Four stroke Altenator

[dray0151]

I am looking to install a Perko battery switch on my Mercury 150. Have looked at both one with the alternator field disconnect and one without the field disconnect. I understand the purpose of the disconnect is to protect the alternator in the situation the engine is running and the switch is turned off. Question from me is I read that on an alternator that is unitized and has no external regulator you cannot install the alternator disconnect. Does the 2012 mercury 150 serial number 1B925382 model 115OF13HD? In the parts diagrams for my engine I can find no part that is a regulator or a rectifier.

[boats.net]

The regulator is inside alternator and not sold separate. You should never turn battery switch off while running motor, it could damage alternator.

[dray0151]

I understand you should not turn it off with the engine running, my biggest question is since the regulator is internal am I correct you cannot install a battery switch and connect the alternator disconnect field as the regulator is internal to the alternator.

[boats.net]

Yes you are correct.