1988 Merc 100, serial OB300685, inline 4 cyl.
Looks like it has a regulator, but I am getting 15.8 volts while running. As best I can tell from the Seloc manual, the 2-3" square black box is a regulator. Looks like this one. http://www.iboats.com/mall/partfind...gd_poid=111805&gd_row=89&**********=941856151
Did some reading about the charging systems on older models without a regulator, and this is acting like it doesn't have one. The battery is brand new and fully charged. The voltage does drop when I put a load on it such as the trim tab pump. Tried putting both batteries online, and the voltage stayed high.
So I am assuming the regulator is bad, but in the interest of not just throwing fairly expensive parts at it, figured I would ask those who know these systems well. Do these regulators default to max output if they go bad? Is there such a thing as a typical failure anyway?
Have a Humminbird fish finder GPS which is where I was reading the voltage from. It will take 10-20 volts input, so shouldn't hurt it at this point, but this isn't good for the batteries. Probably isn't good for the marine radio or stereo either.
Some thoughts?
Looks like it has a regulator, but I am getting 15.8 volts while running. As best I can tell from the Seloc manual, the 2-3" square black box is a regulator. Looks like this one. http://www.iboats.com/mall/partfind...gd_poid=111805&gd_row=89&**********=941856151
Did some reading about the charging systems on older models without a regulator, and this is acting like it doesn't have one. The battery is brand new and fully charged. The voltage does drop when I put a load on it such as the trim tab pump. Tried putting both batteries online, and the voltage stayed high.
So I am assuming the regulator is bad, but in the interest of not just throwing fairly expensive parts at it, figured I would ask those who know these systems well. Do these regulators default to max output if they go bad? Is there such a thing as a typical failure anyway?
Have a Humminbird fish finder GPS which is where I was reading the voltage from. It will take 10-20 volts input, so shouldn't hurt it at this point, but this isn't good for the batteries. Probably isn't good for the marine radio or stereo either.
Some thoughts?