OK got an alternator question... bench tested at O'reilleys good... believe them as I bought a new one and they tested the old and bought the new one back. Tested Battery... it charges on charger just fine......
but put the two together in the truck and NO CHARGE.... wiriing harness just...
Tested alternator...that tested ok
Tested battery that tested at 12.4 v
Changed wiring harness from battery to alternator
Cleaned battery posts
Still will NOT charge battery
What next????? Someone suggested brushes inside alternator? Can the system test ok and still have bad brushes?