Alternator troubleshooting. 6V92

[Oonrahnjay]

If you replaced one of the rear switches, I would start looking for a problem there. I know my old GM has an engine control switch that will disable the alternator and the front start switch when its on the off position.   

    This is outside my experience so I am not asking as an expert but in this situation, there would be no voltage to the F terminal, right?  And if you run a check and there's no field voltage, that could point to a mis-set switch or the installation-wiring problem that you referred to, right?  But if there is field voltage, that rules both out? 

[stoker]

I removed the F1 wire and supplied the terminal with battery voltage. Still no output. I will now remove the alternator. There is a pretty good generator shop in town.

[stoker]

I took the 50DN to the alternator shop and he said he had no way to run it on the bench and was not familiar with them. He did quickly determine two of the three negative diodes were bad but was not interested in going further. I took the alternator home and have now ordered all three negative diodes. Do you guys think that would cause no output? I have looked for a service manual online and can't find anything useful. I would love to test all the components while it is on my workbench. It is a lot of work to remove that thing.

[LuckyChow]

A 50DN is one of those things I'd trade in for a rebuilt unit or, I'd pick up a used one from a take-off unit.  There are so many transits being scrapped that the last two I bought were only $200 each used. 

[luvrbus]

Talk to the guy @Kirks phone 1-313-933-7030 and they have the parts you need

[eagle19952]

looked here ?

http://delcoremy.com/Installation-Instruction-Sheets/Service-Manuals-Alternators.aspx