What was found
(CAN) PILOT REPORTED LOST GLIDESCOPE ON APPROACH AFTER LANDING GEAR WOULD NOT RETRACT. GEAR SWUNG, ELECTRICAL WIRING INSPECTED, BATTERY REPLACED, VOLTAGE REGULATOR ADJUSTED (MAIN). AIRCRAFT RELEASED AND TEST FLOWN - NO FAULTS FOUND. COULD NOT DETERMINE CAUSE OF ELECTRICAL FAILURE EXCEPT SUSPECT VOLTAGE REGULATOR WAS ADJUSTED TOO HIGH AND OVERVOLTAGE RELAY KICKED SYSTEM OFF. IT WAS A COLD DAY, BATTERY WAS WEAK AND AIRCRAFT COLD-SOAKED.