electrical problem 1989 45 hp

[herm]

First time on forum.
hello,
I have a 1989 4cylinder 45hp mariner and my problem is that my engine is over charging to 19 volts and keeps blowing fuses.
I'm new to boating and any help would be great.
P.s the rectafier was changed last time it was serviced.
Thanks herm

 

[pilot481]

Re: electrical problem

Yes that is too high of a charging voltage for sure. 3 most common reasons, grounded or shorted wires, bad rectifier, bad battery. Get your battery load tested,

 

[galamb]

Re: electrical problem

Do you have a "Marine" battery?

Merc's "rectified" charging systems eat car batteries for breakfast.

A Marine (or tractor or RV) battery works as a capacitor and regulator for the system - something a normal automotive battery can't do for very long.

If you do, then definately take the above advice which is bang on...