Testing a Regulator / Rectifier combo

[Phoenix]

Okay, so it's a 1977 GS550B with 30,700 miles on the engine. At one point (before I bought it a week ago -so sometime in the last 29 years, 10 months) the regulator and the rectifier were pulled and replaced with a regulator/rectifier combo. The part number on the r/r is SH556-12 3.2 from Shindengen. I've done searches for this part or anything on it because I believe it's bad. The engine runs fine, till you turn on the lights, then you've only got about 15 minutes before she dies out. The only thing that's been done to it since the lengthy night trip home was messing with the points. I'd hate to pay the money for the r/r replacement to find out the problem is something else. The old 77 service manual I have only has a no load test for the individual units which calls for realigning the three phase circuit path.

I don't suppose anyone can tell me how to test the regulator/rectifier combo? Or has a wiring diagram for the r/r charging system.

[RMC]

If you'll go back out the main web page for this site and then go to the area listed as "In the Garage" scroll down until you see the Stator Papers and it has information for testing the R/R.

[Steve]

For your convenience, just click HERE.

In the meantime, let me toss a quick welcome your way before the "official" guy chimes in.


HEY BASSCLIFF! Another newbie. \\/


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[BassCliff]

Been there, done that!

For your convenience, just click HERE.
In the meantime, let me toss a quick welcome your way before the "official" guy chimes in.

HEY BASSCLIFF! Another newbie. \\/

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Mr. Steve,

I've already "officially" welcomed Mr. Phoenix in this thread. He's got pictures there and everything! Not bad for a noob!

Good to see you again, Mr. Phoenix. :-D

Thank you for your indulgence,

BassCliff

[BassCliff]

Mr. Phoenix,

You will need a schematic for your r/r. Basically you want to check all the diodes to make sure they are passing electricity in one direction only - a measurable amount of resistance one way, then reverse the leads and it should show infinite resistance. If you have a diode checker setting on your meter then use it, but it's the same principle.

Thank you for your indulgence,

BassCliff

[Phoenix]

Yes a noob

Definately new to the site seeings how I thought I searched my tail off for something on the r/r wiring only to find it right there under my nose the whole time! Anyway, it seems the r/r is the problem. So I guess I'm locked into day time driving only... I better get some tags for this sucker.