voltage regulator question

surrender

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Jan 25, 2009
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1985 115 Johnson. Put motor on boats and its running great but not charging. Went through the tests for the stator and its putting out per specs. After trying to figure out why its not charging I found the purple wire going to regulator off the terminal strip was not getting 12 volts with the key on. Found wire cut under helm. Previous motor had three wire rectifier and didnt use purple wire. Anyway the question is would the regulator burn up or fail if motor was run a few times without the 12 volts going to the purple sensor wire? I have hooked up the purple wire and now get 12+ volts to it and it seems that I may be getting some charging but I have only run the motor on the hose up to about 1500 RPM. Have not checked charging status while running under a load in the water. May just need a new regulator.

Note: tach works but if red wire coming off regulator going to battery is disconnected tach doesnt work
 

fireman57

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Aug 24, 2004
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3,811
Re: voltage regulator question

these engines really don't charge much at low rpms if I remember correctly they only charge at 1.5 amps when they are charging well. The red wire is always a hot wire.
 

Will Bark

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Aug 1, 2010
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1,470
Re: voltage regulator question

Agree with fireman; put multimeter on battery with engine off get a reading then crank engine; if you have a higher reading then you are charging and the faster you go (on the lake) then you are good to go.
 

WernerF

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Sep 5, 2011
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Re: voltage regulator question

I don't think it's harmful for the stator or regulator. Whenever the engine fuse blows during running (eg. a short in trim relay cicuit) you get exactly this, no +12V on the purple wire. You have the same condition for a short time when shutting off the engine from high rpms.
 

boobie

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Nov 5, 2009
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Re: voltage regulator question

Put a volt meter across the battery and run it. If you see 13.8-14.2 volts you are okay.
 

surrender

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Re: voltage regulator question

Thanks for all the responses. Like I said, ran it on the hose and will retest on the water at higher rpm's. If the regulator is bad I think I'll just go back to the three wire rectifier from my old motor. It was a new one I purchased and only used for a couple of trips on the old motor. I believe both stators put out nine amps so it should be fine. I'll just watch out for over charging.
 

fireman57

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Aug 24, 2004
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Re: voltage regulator question

Since it is an open system it may appear to overcharge once in a while but it will not hurt anything.
 

surrender

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Re: voltage regulator question

On my 88 special it would overcharge and I'd just run the lights or cycle the bilge or livewell pump. After thinking about it my just put new regulator on if it is not fixed. Found the CDI one online for $62 plus shipping.part number 193-4204.
 
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