generator third brush adjustment

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    How do you adjust the third brush on a 1927 S80 generator? I do not know how to loosen the third brush or which way to move it for more amps. Thanks for any advice!


    This may help


    Thanks for the link. Yes, I had already reviewed that information but I am still at a loss. The end plate on my generator, which is a Pierce-delco unit, does not have the pictured screw so I am still not sure how the third brush is secured.





    I am assuming that most Delco Generators are similar. I have mine apart out of my ’33.

    In the cover plate nearest the brushes is an external screw that holds the third brush tension plate


    On the flip side the 3 rd brush is on a ring that rotates around the shaft. There is a plate that when the screw is tightened it acts like a a disc brake

    and keeps the ring from turning. Loosen it and it rotates.


    And here is a piece on the adjustment.


    Forgot. The third brush is the one on the right in the second picture and is the one that rotates when the hold down is loosened.

    Yours may be totally different but I hope this helps.


    With or without the diode addition to the cutout, it’s a Best Practice to get in the habit of eyeballing the ammeter immediately after engine shutdown to be sure the needle remains at zero. If at discharge (and no current draws such as lights left on), the cutout points are stuck, in which case immediately disconnect the battery and remedy the condition.


    Thanks for all the help! I finally figured out how to adjust the third brush. The S80 generators do not have the screw on the end plate. Instead, as described in the tune up guide, there is a tab (the tune up guide calls it a handle) inside the generator that you move. It is held in place with a friction fit and you have to tap it with a screwdriver and hammer ever so slightly to increase the output. You can use a screwdriver to pry it back to decrease the output. I have attached a picture of the “tab””. The wiggly yellow line points to the tab.”

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