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Discussion Starter · #1 ·
I've got a 1971 CL450 and the charging system isn't working properly. (As a side note, a fully charged battery will let me ride 5.7 miles before I'm stranded on the road.) I suspect the regulator and the rectifier seems to be acting up as well. Are there any good aftermarket solutions for these? All I can seem to find are used things and they could be no better than what I already have.
 

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Be sure your battery is ok before you mess with anything else.
Seems like a fully charged healthy battery will take you more than 5-7 miles.
These batteries are minimal to the task, and fragile - getting run down more than a couple of times hurts them bad.
Batteries can be bad right out of the box, so don't just assume it's ok............

And like everyone here, we should all own a couple of Battery Tender Jr.'s
 

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Sensei
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Once you are sure the battery is good, start the bike and unplug the coupling to the alternator.... Read AC voltage across pink and yellow (alternator side) at idle and 3000+ revs
You SHOULD be getting about 18VAC or more at idle and at least 30 to 35VAC at 3000RPM...... If not, its an alternator problem......

I also suspect a "bad" battery that just takes a "surface charge"......
 

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Discussion Starter · #4 ·
Well the battery is brand new and the regulator had a burnt wire on it, so that's why I was suspecting it.
 

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Sensei
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Understood..... However, the regulator just controls "overcharge" and the alternator and rectifier should charge the battery without the regulator in circuit (just unplug it).... They can both be tested by "output"
....VAC output as I discribed for the alt....
...VDC output across the red/white, and green rectifier wires ....(plug the alt back into the harness)
....( BTW, Which color regulator wire was "burnt"?... I suspect yellow...)
...The regulator is usually one of those "swap in a known good one" checks.......
....The rectifier is simply a matter of direction (polarity) vs continuity, and can be checked with an ohmmeter....
But to quote Bill..."Batteries can be bad right out of the box, so don't just assume it's ok............"....Check it.......Specific gravity reading should tell.....
 

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Discussion Starter · #6 ·
I did the alternator test and it's working fine. With the regulator in place the battery is only getting about 12.4 v at idle and 12.6 or so at 3k. The rectifier is letting some AC through as well.

In the regulator, the black wire was burnt.
 

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Sensei
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You were correct.... You need to replace both rectifier (shorted diode as AC "leaks" through), and regulator (Black wire is the "dump excess voltage" trigger current)
If you decide to use a combination unit, get a wiring schematic of it or the bike it comes from...
 

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Sensei
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The "later" ('74 on) Honda components work fine, are available, and you can plug them right in.... Usually, two don't go bad at once, and you can simply replace the "bad" one...... A Radio Shack rectifier works, as does the "Oregon" one....
 
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