brushes are easily replaced ,diode can be checked with a multimeter,diodes don't usually fail unless polaraties are reversed or alt is shorted out ,one thing to bear in mind is alts fail because of mechanical failure due to the slip rings ,these keep armature in alignment ,so check for exessive end play.if exessive play is felt then you would be better of getting a recon ,usually a exchange service .
mech monster, October 2011
