1992 60 hp overcharging - upgrading to a voltage regulator

jakerska

Recruit
Joined
Sep 24, 2012
Messages
5
I have a 1992 Mercury 60hp on my pontoon. 0D112775 serial number. Has a red stator. Starts and runs great. Charges a little too well also. Consistently has the voltage gauge pegged. Checked with a different voltage meter, puts out around 17 volts. Being a pontoon, there aren't many accessories being ran to use up the voltage being cranked out. So I figured it would be worth replacing the voltage regulator. Went on ***************** and entered in my serial #. Showed a voltage regulator in the schematic so I purchased an aftermarket one. I was a little confused as I had replaced the rectifier one time in that motor years ago when it was not charging, and I didn't remember seeing an item looking like a voltage regulator under the panel. But I had confidence as I had entered my specific serial number and ordered it (from a separate source). Got in the water to put it in, got things taken apart, and a rectifier is exactly where the regulator would go. I have read many blogs about this and many people have problems with newer AGM and maintenance free batteries. I put a new conventional battery in it last year, and for kicks I took the starting marine battery out of my fishing boat and put in in the pontoon to try. Same outcome. 17-18 volts.

So here is my question: Is it possible to upgrade this system from a rectifier putting out a constant charge or upgrade to a voltage regulator. By the time I pay the restocking fee on the regulator and shipping back, returning it doesn't seem to make much sense. I would prefer not cooking my starting battery putting around the lake. Like I mentioned, I have read through many blogs on this, although I haven't seen anyone change from a rectifier to a regulator. Thank you in advance for you time!!!
 
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Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,901
The red stator is a 16 amp stator. Your current rectifier gets AC voltage from the stator (yellow wires on my last engine). Your current module contains 4 diodes and changes the voltage to DC. Since there is no regulation the output is proportional to engine rpms and 16v is the norm from the manual for 1000 rpm (as I recall) so your 17 at a higher rpm is normal.

Purchasing a module with a built in regulator for a red stator engine (my 2002 90 hp. merc 2 stroke for a model) would do your job nicely. Nothing extra to worry about. The large red wire output wire goes where your current red wire goes. Any extra red wires can just be rolled up and taped to prevent shorting to something as they aren't necessary for your engine. Ensure the ground (black wire) goes to the same ground that your battery - is tied.....should be the same spot where your current rectifier module ground wire ties. That's it.

This should limit your max current and reduce your charging voltage to 14v max, all depending on the condition of the battery and it's current charge level. I agree that a red stator, unregulated, for a low consumption electrical system, is way too much.
 

jakerska

Recruit
Joined
Sep 24, 2012
Messages
5
Thanks so much for the info. I really appreciate it!! Any guesses on the bolt size which holds in the regulator? There are pre-tapped holes there for a regulator already. Just don't know what to size and pitch to buy to hold the regulator in place. Thanks!
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,901
No. How about the bolts holding the current diode in place? Surely Merc wouldn't tap 2 different sized holes for similar items mounted on the same plate....not cost effective.
 
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