18HP B&S charging circuit problems (again)

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  #1  
Old 07-19-15, 12:22 PM
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18HP B&S charging circuit problems (again)

About a year back, I was here with trouble on my B&S charging circuit. In the end, I had converted to a two wire system with parts I had laying around, then had to order in a regulator.

A few months ago, my charging circuit failed again.
I went back and reviewed the thread because I don't remember any of this (thread is here#b )

Seems that I went dark after ordering a new regulator- and I remember it was charging (although barely) all winter.

I just went out and checked, and that regulator is putting out 0VDC again.

I checked the two-wire coil, and found that it's putting out about 10v at idle, and 24v at high RPM. My understanding is it should be putting out ~30V so I'm wondering if the coil is junk, too. Is 10v at idle normal? I'd love it to charge without being at full rpm- I only ever run it at top speed when snowblowing. It's just too loud for putzing about the property and mowing the lawn at that speed.

I'm prepared to replace the whole circuit- preferably with a high output single wire- if someone could help me identify the part I need.
From the old thread, my engine model is 422437
A search for this I'm seeing dozens of alternators available, mostly two wire ones. One wire seems to be the way to go, to me...
 
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Old 07-19-15, 08:48 PM
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10v AC would be about right because after it's rectified it will be approx 14v DC.
 
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Old 07-20-15, 08:35 AM
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Well, that sounds like good news, then.
All I need is a new rectifier, again.

Is there a certain brand/type that's more reliable than another? Every place I've seen seems to have the same exact part for anywhere between $20 and $90. Last one I bought lasted about six months- not sure why it died. Heat, maybe? It's bolted pretty close to the exhaust.
 
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Old 07-20-15, 08:43 AM
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If you can park it anywhere near a 120 volt outlet, add a battery tender or equivalent for about $25 and always have a full charge.
 
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Old 07-20-15, 09:26 AM
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I've been charging it up between uses- problem is the PTO uses an electric clutch that draws a lot of juice.
Mowing the lawn is enough to almost completely drain the battery. Over the weekend when I did this, it dropped below 10v just as I was finishing up and the clutch released- no more mower deck.

Afraid I actually need the charging circuit to work in this case. Hoping to add some nice high output headlights before winter sets in, too.
 
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Old 07-20-15, 11:40 AM
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If it's a dual Alternator, one circuit for charging, and one circuit for auxilliary devices (lights, heated hand grips, cigarette lighter, etc), can you switch the leads, and attend to the more important function . . . . keeping the Battery charged ?

That might carry you over; plus complete the diagnosis that the Alternator is at fault.
 
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Old 07-20-15, 12:19 PM
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Extend the wiring so that you can mount the bridge away from heat. Heat is a killer of electronics.

You could use a bridge like that shown below. You could make up a mounting plate to act as a heatsink and a way of mounting the part.

MP5005-BP Micro Commercial Components (MCC) | Mouser
 
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