35 amp motorola alternator

[captjake]

took my alternator out to replace belt and clean up. I was looking at the plate that has the positive output stud and cant figure out how the plate isnt grounded to the case at points A&D in the photo. also underside shows that the stud (C) is soldered to (B) . so question how the heck does the positive voltage arrive at (C) ....what is (B) and why does the whole plate short out and (A) and (D)? I'm really stumped and tired of staring at the alternator as if its going to yell the answer. 4771

[sastanley]

Hi, captjake.
There are little plastic isolation bushings on A & D that keep the plate & studs/nuts separated....they are easy to lose & drop off if you take the plate off. (don't ask me how I know this :D)

The stud "B" I am pretty sure is one of the diodes on the diode plate. "C" is obviously the output stud for charging the batteries.

[captjake]

Thanks, the isolation bushings would make sense for isolating the plate from the case and ground, but (B) and (C) are soldered to each other on the underside with no visible connection to anything else. Is the plate itself made positive by (D) without a bushing? sorry still confused. If I had it here i guess i could do a continuity test of (A),(C),(D) and the plate but not for another week. Hope I get help figuring it out before that.

[sastanley]

Sorry I can't help much more with the details. I took my alternator to a local alternator shop and the technician explained all that stuff to me. I don't remember why now, but I had removed one of those A or D nuts, and lost the bushing into the bilge. When it wouldn't charge after that & I took it to the alt. shop, I was provided with that information & he told me I had grounded the diode plate by losing the bushing(s).

It is still a pretty mysterious spiral wound pile of copper to me. :o

[captjake]

Thanks for your help. Even if we haven't solved the entire problem (yet) I find that anytime someone is willing to post a reply to assist another takes some of the load of the problem. I'll continue to pursue the answer and if I get it somewhere else I will be sure to return to this great site to share it will you all.
Have a great day,
Cap't Jake