1986 75hp Mercury is over charging

[truhl_58]

Took the boat out this last weekend everything was running perfect but i noticed it was over charging normally it charges about 14 volts + or - but this time it was charging 16 + volts. Could this be the rectifier or is it the regulator?

 

[Barnacle_Bill]

I don't believe you have a regulator on that motor. Just a rectifier. Check the battery cables at both ends. The must be clean and tight and no corrosion. Have the battery load tested and be sure it is a marine battery. Yes there is a difference.

 

[truhl_58]

Funny thing the only thing I did do is re-install the the 2 marine batteries I had out for charging. I use 2 batteries hooked parallel. I will check the connections. Thanks

 

[Texasmark]

If you never noticed 16 volts before when you previously looked then you may have a regulator as they usually limit the peak voltage to 14.5 v, above 1000 rpm. A non-regulated supply runs 16 volts above 1000 rpm (says the op. manual). If the two big batteries you installed were in a serious state of discharge you may have burned out the regulator. Charging circuits are made to "maintain" a previously charged battery, not charge them from scratch. Smoking gun for the regulator would be heat destroying the regulator components.

Mark

 

[truhl_58]

Batteries were fully charged before installing them. Connections were all tight. Sounds like the regulator or is it the rectifier? Which brand of rectifier or regulator is better or are they all the same? Thanks for all the info.

 

[Texasmark]

Batteries were fully charged before installing them. Connections were all tight. Sounds like the regulator or is it the rectifier? Which brand of rectifier or regulator is better or are they all the same? Thanks for all the info.

What do they sell on here? Have heard no complaints from others on iboats parts and the ones I have purchased were what they were intended to be.