Roundback vs. Squareback alternators?

This looks like it was either set up to be grounded or someone didn't put the correct brush with terminal on it.
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Normally if its set up with both brushes having insulated holders,run a wire to ground like I show in the thread Dana linked to.
No. Take out the insulating fiber washer only. All you're doing is making sure that brush is grounded.
May need a metal washer or two. Or trim the brush holder insulation. The insulator is raised where the washer sits.
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