MEP 531A Alternator Wiring Question

[Craig H]

Folks, I could use some help. I recently purchased an MEP531A at auction. When I got it I found that the alternator was new, installed to the engine, but not wired. Removing the alternator cover I see that there are 4 brushes (2 on the inner ring and 2 on the outer ring) and three loose wires that disappear back into the alternator. Two are the field wires and go directly to the mil-spec connector. From the schematic the other wire looks like it comes from a stator winding and is part of the exciter? How do I wire this correctly?

A couple questions: Is the exciter winding in the schematic the same as the rotor winding? Is the inner ring or outer ring for the positive field wire (or does it not matter)? I am thinking that exciter wire goes to a brush on the same ring as the neg field wire and I use a separate wire to connect the two brushes on the positive field ring. Any help would be much appreciated.

Thank you.
Craig

 

[WWRD99]

Folks, I could use some help. I recently purchased an MEP531A at auction. When I got it I found that the alternator was new, installed to the engine, but not wired. Removing the alternator cover I see that there are 4 brushes (2 on the inner ring and 2 on the outer ring) and three loose wires that disappear back into the alternator. Two are the field wires and go directly to the mil-spec connector. From the schematic the other wire looks like it comes from a stator winding and is part of the exciter? How do I wire this correctly?

A couple questions: Is the exciter winding in the schematic the same as the rotor winding? Is the inner ring or outer ring for the positive field wire (or does it not matter)? I am thinking that exciter wire goes to a brush on the same ring as the neg field wire and I use a separate wire to connect the two brushes on the positive field ring. Any help would be much appreciated.

Thank you.
Craig

I have a 531 outside...if you can post a pic of what you're looking at I can take a look at mine and see how it is hooked up.
Rich

 

[Craig H]

I have a 531 outside...if you can post a pic of what you're looking at I can take a look at mine and see how it is hooked up.
Rich

Rich, Attached is a photo of the alternator with the end cap removed. I wired it how I think it goes but could really use a check. You can see the 4 brush caps. Note that I had to manufacture two as they were missing and I couldn't find anyone selling the part (They do work properly).

Side note: the brushes were also missing and hard to find. Eventually I found them at advancecarbon.com for a reasonable price.

The three wires from the top were loose (not even stripped) when I got it. I added the red wire to connect the two brushes going to the outer ring. I have the exciter wire going to the brush cap circled in black on an inner ring. That is is the same ring I have hooked to the negative field wire. I don't know if this is correct and I don't think one can tell from the schematic.

Thanks again for any help.

Craig

 

[WWRD99]

Rich, Attached is a photo of the alternator with the end cap removed. I wired it how I think it goes but could really use a check. You can see the 4 brush caps. Note that I had to manufacture two as they were missing and I couldn't find anyone selling the part (They do work properly).

Side note: the brushes were also missing and hard to find. Eventually I found them at advancecarbon.com for a reasonable price.

The three wires from the top were loose (not even stripped) when I got it. I added the red wire to connect the two brushes going to the outer ring. I have the exciter wire going to the brush cap circled in black on an inner ring. That is is the same ring I have hooked to the negative field wire. I don't know if this is correct and I don't think one can tell from the schematic.

Thanks again for any help.

Craig

Ok let me take the cap off and see if I can get a good pic of where the wires go. As far as parts go you can go through the Dewey supplier to get parts...I did that to find what I needed when I got mine....I was missing the oil pressure sensor and a few other small things....really helped at least getting part numbers of what I needed...I ended up finding the parts elsewhere since I don't pay govt prices...the manual is 716 pages of insanity.

 

[Craig H]

Thanks Rich. I had the electronics box off so I could wire it. I think there is room to pull the end cap off and take a picture. I really appreciate it.
Craig

 

[Craig H]

Does anyone have a picture of the alternator with the end cap off? I am still in need of wiring assistance.
Thank you all,
Craig

 

[CallMeColt]

Does anyone have a picture of the alternator with the end cap off? I am still in need of wiring assistance.
Thank you all,
Craig

Not sure if you ever figured it out, but I just got through taking one of these apart for not making power. Not sure why it wasn't, but I shared a few pictures before I did & it was with the rear cap off. Here is a link;

MEP 531A Fix-up Thread

Howdy all, Been a while since I started one of these! Got myself a MEP 531A at auction. Definitely had a bunch of hands in it, but, I got one of the best deals that was had in a while on one. I knew right away the breaker was pushed into the panel and the cover over the gauges was...

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