What was found
WHEN NR 2 PROP HEAT IS CYCLED TO 'A' PHASE,BOTH 'A' PHASE AND RT TRU CIRCUIT BREAKER POPPED AND THE RT ELEVATOR HORN HEAT CAUTION LIGHT ILLUMINATED. R & R NR 2 PROP LEADS, GROUND RAN ACFT, OPS CHECKED GOOD. WHEN NR 2 PROP HEAT CYCLED TO 'A' PHASE, THE RT TRU CIRCUIT BREAKER POPPED AND THE RT ELEVATOR HORN HEAT CAUTION LIGHT ILLUMINATED. R & R BRUSH BLOCK, OPS CHECKED GOOD. NR 2 PROP BLADES 1 AND 3 RT 'A' PHASE LIGHT DOES NOT ILLUMINATE. VOLTS READ 88-69 AND THE EMERGENCY LIGHTS FLICKER DURING 'A' PHASE CYCLE. R & R 'A' PHASE CURRENT LIMITER IN NR 2 AC CONTACTOR BOX. GROUND RUN, OPS CHECKED GOOD ON BOTH TIMERS.