On January 23, 1994, about 1350 hours Pacific standard time, a Rockwell Aero Commander AC-112, N1084J, right landing gear collapsed while taxiing to the hangar after landing at Harry Sham Field, Modesto, California. The pilot was completing a visual flight rules (VFR) local personal flight. The airplane, registered to and operated by the pilot, sustained substantial damage. The certificated private pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at Harry Sham Field at 1330 hours. The pilot submitted a Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2. He indicated in the report that he made two takeoffs and landings on runway 10R. After completing the second landing, he made a right turn off the runway and taxied toward his hangar. While taxiing between 3 and 4 miles per hour, the landing gear warning horn sounded and the right main landing gear down light went out. The pilot immediately shut down the engine and then the right main landing gear collapsed. The pilot also did not indicate in the aircraft accident report when the last annual inspection was completed. Nor did he indicate the total flight hours on the airframe and the total flight hours since the last annual inspection. Mr. Tom Rouch, Top Gun Aviation, Inc., Harry Sham Field, said in a telephone interview conducted on June 6, 1994, that he repaired the airplane. During the maintenance repair, he found the right main landing gear wiring considerably worn and chafed. He said the wiring was the original wiring. This condition caused an intermittent operation to the hydraulic pump. During normal operation, the hydraulic pump maintains pressure to the landing gears when they are extended.