What was found
(CAN) 1ST INSTANCE DURING GROUND ENGINE RUN AC GEN CAUTION LIGHT CAME ON - AC GEN REPLACED. 2ND TIME AC GEN CAUTION LIGHT CAME AND AIR TURN BACK WAS INITIATED, SUBSEQUENT TROUBLE SHOOTING 1) FOUND WIRE 2421-10003CBC IN #1 AC CONTACTOR BOX CHAFING AND ARCING TO CURRENT TRANSFORMER T1. WIRE 2421-10003CBC REPLACED AS PER STD PRACTICES. CURRENT TRANSFORMER T1 REPLACED IAW AMM 24-21-01. 2) ALL 3 SOCKETS @ 2421-P29 REPLACED IAW STD PRACTICES. AC GENS OP CHECKED SERVICEABLE AS PER AMM 24-21-01. DUE TO PLUG NOT BEING INSTALLED AND PROPERLY TIGHTENED. (TC# 20190502018)