I have 2 alternators and both tested bad but I'm wondering if the brushes were just bad or it's that alternator.

Do you think these wore brushes would show a failure when bench tested?

Also, the chinese alternator from Advance has different wiring in the back.
On the older bosch, there's a + sign next to the terminal that I hook to car but on the advance alternator, it's a W sign. The + sign on the advance alternator has another electronic part plug into it. Is it possible the that the electronic part on the advance alternator is plugged into the wrong terminal?

Any advice would be greatly appreciated.

Thanks,

pete

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