What was found
MASTER CAUTION ILLUMINATED DURING TAKEOFF WITH LT AC BUSS, LT TRU, & PITOT HEAT 1 CAUTION LIGHTS. REJECTED TAKE OFF AT APPROXIMATELY 60 KTS. COMPLIED WITH LT AC BUSS CAUTION IAW FIM TASK 24-20-00-810-803. FOUND EPCU FAULT CODE 25, VERIFIED LT AC GENERATOR STILL OPERATIONAL WITH LT AC BUSS CAUTION ILLUMINATED. SWAPPED LT & RT CONTACTORS, BOX CONTACTORS K1 AND K2. OPS CHECKED GOOD. LT AC BUSS CAUTION REMAINED EXTINGUISHED. RETURNED ORIGINAL K2 CONTACTOR TO ORIGINAL RT POSITION. SUSPECT BAD K1 AC CONTACTOR. R & R LT K1 AC CONTACTOR. OPS CHECKED GOOD. COMPLIED WITH OPS TEST OF AC VARIABLE FREQUENCY GENERATION SYS IAW TASK 24-21-00-710-801. OPS TESTED GOOD. COMPLIED WITH OPS TEST OF LT TRU AND LT PITOT STATIC PROBE HEAT IAW AMM TASKS 24-31-21-710-801 AND 30-30-00-710-801. BOTH OPS TESTED GOOD. ACFT OK FOR CONTINUED SERVICE.