What was found
(CAN) PILOT REPORTED ELECTRICAL FAILURE DURING TAXI. INVESTIGATION FOUND ALTERNATOR HAD A LOOSE HOUSING. ALL LOCKING TABS WERE SECURE ON THRU BOLTS THAT HOLD THE FORWARD AND AFT CASE HALVES TOGETHER, YET THECASE WAS CLEARLY LOOSE AND THE TWO SECTIONS FRETTING AGAINST EACH OTHER.AS MUCH AS .125 IN. CLEARANCE WAS FOUND DESPITE APPEARANCE THAT ATTACHEMENT BOLTS HAD BEEN LOCKED TIGHT. ALTERNATOR EXCHANGED FOR NEW PART.