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Charging

S

steve from staten island

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Im almost positive the alternator is weak. Only 13 1/2 at the most volts and with a carbon pile when i load it up to 50 amps the engines slows down and the alternator whines the voltage drops to well lesss than 13. Any thoughts and thanks for any help
 
Bad diode?
 
I used to just solder in another diode.

Easy to test them.

...but you have to have access to parts, which may as well be equal to having a few alternators laying around.

Rockauto?
 
Sounds like toast to me, Rockauto....
 
NAPA premium remanufactured.
60 amp 2 pulley, here is $60.
Dont know about Rock Auto, but I trust NAPA quality.
And if you know what you're doing, they list all parts to rebuild it yourself.
 
YY1 said:
I used to just solder in another diode.

Easy to test them.

...but you have to have access to parts, which may as well be equal to having a few alternators laying around.

Rockauto?
Click to expand...
Then ya got resin-core, acid-core solder and no more Radio Shack for an easy place to go get it!
 
Gentlemen,
My vote is an OPEN diode. The round back alternators used diodes (3 positive polarity diodes and 3 negative polarity diodes) pressed into the heat sinks. The square back alternators used 3 positive polarity diodes and 3 negative polarity diodes spot welded to heat sink and are NOT individually replacable.
In both cases, the alternators are connected in a three phase full wave bridge arrangement. The loss of one diode in EITHER the positive or negative circuit will result in HALF of the published amp capacity; the voltage will remain at 14 volts (+/-) except under high load.
Bob Renton
 
RJRENTON said:
Gentlemen,
My vote is an OPEN diode. The round back alternators used diodes (3 positive polarity diodes and 3 negative polarity diodes) pressed into the heat sinks. The square back alternators used 3 positive polarity diodes and 3 negative polarity diodes spot welded to heat sink and are NOT individually replacable.
In both cases, the alternators are connected in a three phase full wave bridge arrangement. The loss of one diode in EITHER the positive or negative circuit will result in HALF of the published amp capacity; the voltage will remain at 14 volts (+/-) except under high load.
Bob Renton
Click to expand...
AND I reiterate my previous post about no 'Radio Shack' anymore... Where do amateur electricians go these days? Inquiring minds want to know.
 
Why replace the entire alternator when it just needs repaired ? This is especially true if you are trying to maintain originality. Most, but not all "rebuilders", will replace brushes, noisy bearings, but NOT stator coils, rotors or diodes, but media blast the housings to give the appearance of new/rebuilt condition. True, some repair methods will require special tools (diode press, drive shieve puller/installer, resistance tester, etc.) and the knowledge and skill to use these tools. Alternators are simple devices.....for my money, I'll just fix my original date coded alternator when and if it needs service. This is just my opinion.
Bob Renton
 
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