What was found
CLT - FLT 2673 - EN ROUTE FROM BOS TO TPA, THE APU EGT GAUGE WENT TO ZERO DURING FLIGHT. THE APU WAS IN USE AS THE NR 1 GENERATOR WAS ON MEL. FLIGHT DIVERTED TO CLT AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE FOUND A LOOSE CONNECTION ON THE EGT HARNESS CONNECTOR. TIGHTENED CONNECTOR. REMOVED AND REPLACED APU EGT INDICATOR (P/N 152BL802A) AS PRECAUTIONARY. OPS CHECK GOOD. (M)