if one of the brushes is grounded ( intentionally or accidentally ) we must say thanks God is not the one getting the blue wire, because if so, will inmediatly short out and burn the wire as soon you put the key in RUN.
Very Very true
It's still important to disconnect both field wires when checking for shorted fields. If you leave the blue one hooked up when checking for a shorted field you will almost always get a false positive. The blue wire also directly, or indirectly, connects to solenoids, coils and such so it will tell you there is a ground when it is just current finding its way home through another device.
My apologies if I didn't explain why.
