can't find post

roosteroffroad

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Joined
Jun 10, 2003
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I read an article a while back with instructions on testing a rectifier and didn't copy it. "Guess what" now I need the info. If anyone has this information or knows of the post, It would sure help me and my son get back to our favorite fishing spot for fathersday. It's on a 1983 150hp Black Max.
 

12Footer

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Mar 25, 2001
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8,217
Re: can't find post

I can tell you how. Map-out on a piece of paper which wire goes where, and disconnect the rectifier.<br />With an ohmeter, test between each of the four posts of the rectifier, then turn the leads around,and test them again. Between each set of two, you should get a reading (continuity) only in one direction ,and when you switch the polarity of the leads, nothing.<br /><br />If you get a reading in both directions, that leg of the rectifirer is shorted.<br />If you get zero reading, that leg of it is open.<br /><br />What a rectifier is in fact, is four diodes in a single package.<br />Diodes allow current in only one direction. Your rectifier has four of them, end-to-end. These four diodes connected like this are also called "Bridge networks",or "bridge rectifier", and are used in anything that plugs into the AC wall current, like TV.Radios, and such, to convert AC current to DC. Your takes the AC from the stator ,and converts it to DC.<br /><br />For that reason, any TV shop, Radio Shack, or auto electric shop can also test it . I'll look for a pic of a rectifier.
 

12Footer

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Mar 25, 2001
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8,217
Re: can't find post

0236.GIF
 

Paul Moir

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Nov 5, 2002
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6,847
Re: can't find post

12Footer's test will only work if you have an analog meter. If it's digital, use the setting called 'diode check' or (diode schematic symbol, you'll have too look it up 'cause ubbs won't let me draw it) instead of ohms.<br />Reason is, for anyone who cares, the resistance test voltage on digital meters or VTVMs is extremly low, and diodes have a large voltage drop of about .6v (silicone) That's why they heat up, btw.
 

roosteroffroad

Recruit
Joined
Jun 10, 2003
Messages
3
Re: can't find post

The rectifier only has 3 post on it. I'm guessing 1-load and 2-fields? Should it be checked from one common load to each field for continuity and then reverse checked or do I have something different?
 
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