Rectifier Testing

[RXX]

OK so I have 2 rectifiers in my parts bin. 
 

 

The one on the right has the stock wiring. The one the left I strongly suspect is one of those Yamaha replacements but I forget.

I tested the Yamaha and all the bias things check out so I know it is good, but obviously the wiring is different. The stock is used but if it was put in parts bin by me then I know it should be good but I am not sure how to test it. I am going to pack it but would like to test it first. Can an auto parts store do it or is it a simple test like the Yamaha with a voltage/diode meter? 

[rockmeupto125]

If your meter tests diodes, that'll work. 

 

Do you have a voltmeter on the bike?

[fizzy]

Personally, I would actually install on the bike and test over 10 miles or so with voltmeter connected to battery (13Vish to 14.5V), also check for overheating. There are only 5 wires.

 

[SwampNut]

Testing a rectifier is pretty easy and conclusive, but regulators...complicated.  Because a moto regulator is totally different from a car, I don't expect you can get it tested at any car store.  I really can't think of any conclusive R/R test off the bike.  I'd say put it on the bike temporarily, test voltage at the battery, and go from there.  You can test the diode/rectifier part in resistance mode at the lowest setting, where you should get nearly zero in one direction across each pin pair and infinite in the other.  If that fails, then you know it's bad.  If it passes, then the rectifier part is good but the regulator is untested.  I *think* from old memory that the yellows are the top three junctions here, and the black is bottom.

 

[CALCXX]

The bench testing is good for diode blocking.  

Running is the next step as Fizzy outlined.

I always do a running test and watch the R/R actually control charge voltage.

Usually above 4500 rpm. Watch it work with voltmeter connected. 

Put a load on it like lights, fans and stuff.

Edited August 29 by CALCXX