What was found
ON APPROACH, ELECTRICAL POWER LOSS. AFTER CONTACT WITHTOWER, COMM 1 RADIO TURNED OFF, WITHIN 3-5 SEC C/B FOR ALTERNATOR OUTPUT TRIPPED & INSTRUMENT PANEL LIGHTS DIMMED, AMP GAUGE SHOW DISCHARGE OF BATTERY. TURNED OFF NON ESSENTIAL ELECTRICAL EQUIPMENT & RESET C/B & C/B POPPED BACK OUT. LT C/B OUT & ATTEMPTED RECYCLE COMM 1, TRANSMIT BUT NOT RECEIVE, LOW BATTERY. NO ENG DIFFICULTIES. AFTER LANDING INSPECTED FUSES, FOUND OUTER MARKER BEACON FUSE BLOWN. EXCESSIVE DIRT FOUND ON ALTERNATOR & SURROUNDING CONNECTIONS. BUILD UP CAUSED SHORT IN CONNECTIONS TO ALTERNATOR & CONNECTED COMPONENTS. ALTERNATOR & ENG COMPT CHECKED & CLEANED. BATTERY CHARGED, FUSE REPLACED, RUNUP CHECK & NO ABNORM ELECTRICAL SYSTEM.