Low Charging, possibly incorrect wiring?

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lent0n

Seaman
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May 20, 2022
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1975 evinrude 75hp, bought from a mechanic who did a lot of great work with it.

Starts, runs, all the good stuff no issue,

My dash voltmeter and USB charging both show around 12.9V-13V for charge while at WOT.

I don't have a tach to verify the RPMs at this stage.

I swapped the rectifier since Amazon has them on next day shipping with no change.

I noticed on the bus bar that the one of the yellow rectifier leads doesn't go to anything, I believe this should be connected to one of the other stator leads.

Photos won't upload but I think this might be as simple as moving that other lead onto the other stator output line
 
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Crosbyman

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2 yellows (AC) normal go to the rectifier to become DC or regulated DC if you have a rectifier-regulator to give you flat DC
 
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lent0n

Seaman
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Crosbyman said:
2 yellows (AC) normal go to the rectifier to become DC or regulated DC if you have a rectifier-regulator to give you flat DC
Click to expand...
Yeah that's what I'm saying, but on looking at the setup a second time, I see that the second rectifier contact is bridged over to the other stator wire. I'll double check that there's continuity but doesn't seem to answer any questions. Really hoping it's not the stator because it's just an expensive part.
 
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Crosbyman

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rectifiers for simple testing AC to DC can be these ... AC in DC out
easy to mount high amp capacity but...no regulation .

can't beat $3.00 each
 
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saltchuckmatt

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Jul 19, 2019
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2,791
lent0n said:
Changed it because $25 on amazon is cheaper/faster than testing it. Still getting 12.9-13V.
Click to expand...
I hate to tell you but that's about all you get which is enough really. I'd put the old OEM back on.

I could test that rectifier in about 5 minutes.

New 4 strokes are getting 14.5 but not older 70's....just sayin
 
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lent0n

Seaman
Joined
May 20, 2022
Messages
66
saltchuckmatt said:
I hate to tell you but that's about all you get which is enough really. I'd put the old OEM back on.

I could test that rectifier in about 5 minutes.

New 4 strokes are getting 14.5 but not older 70's....just sayin
Click to expand...

That's actually great news, my fear is a melted stator which I experienced last summer from a poor rectifier connection which is why I'm much more paranoid about it. I don't run a ton of stuff, speedo, voltmeter, small stereo, eventually a tach and all only while running really just keeping LED lights on. My old motor where I had my voltmeter hooked up was a johnson 90s 70hp and it put out around 13.5v, but it had a modern regulator/rectifier setup. I'm not really that picky just wanting to avoid a costly part swap that would be easy to resolve now.

What's your steps to testing rectifiers/stators? I just want something I can use in the future.
 
L

lent0n

Seaman
Joined
May 20, 2022
Messages
66
Crosbyman said:
rectifiers for simple testing AC to DC can be these ... AC in DC out
easy to mount high amp capacity but...no regulation .

can't beat $3.00 each
Click to expand...

I saw a guy do this on youtube! Super intriguing but not looking to push my luck lol!

The net positive of this investigation was I noticed my positive battery terminal connection is broken and that definitely could have led to some serious issues without it being addressed.
 
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