What was found
A TIA WATER HEATER, PN 500-0576-02, INSTALLED IN ACFT WAS RETURNED TO THE REPAIR STATION FOR INVESTIGATION. DURING THE INVESTIGATION, IT WAS LEARNED THAT REASON FOR REMOVAL WAS SMOKE IN THE CABIN AND ELECTRICAL SMELL. INVESTIGATION FOUND A BURNED CRIMP IN THE WINDOW SPLICE CONNECTING THE 16 AWG HEATER WIRES TO THE OVERHEAT TERMOSTAT. ONLY THE SINGLE WINDOW SPLICE CRIMP SHOWED EVIDENCE OF DAMAGE. ROOT CAUSE WAS DETERMINED TO BE WIRES NICKED DURING INITIAL ASSY STRIPPING. A SB IS BEING WRITTEN WHICH WILL INCLUDE A RECALL OF WATER HEATERS IN THAT PRODUCTION LOT. THE WIRE STRIPPING PROCESS IS BEING REVIEWED TO PREVENT RECURRENCE OF THE FAILURE.