As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING SCHEDULED INSPECTION WHEN HEATER SWITCH SELECTED ON, HEATER DID NOT IGNITE. FUEL WAS DRAINING FROM DRAIN. TROUBLESHOOTING DETERMINED NO COMBUSTION AIR FLOW AND CONTINUITY BETWEEN THE TERMINALS OF P/N 94E42-3, (PIPER P/N 757-756) COMBUSTION AIR SENSE SWITCH. COMBUSTION AIR BLOWER MOTOR BRUSHES WERE SHORT, AND WERE REPLACED. COMBUSTION AIR SWITCH WAS REPLACED WITH NEW. GROUND OPERATIONAL TEST WAS SATISFACTORY. (X)