As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WIRING ATTACHED TO THE L1 WINDOW UPPER RIGHT HAND SIDE HAS SMALL ORANGE GLOW WHICH EXTINGUISHES WHEN FWD WINDOW HEAT IS TURNED OFF. GROUNDED - YES. VERIFIED "GLOW" IS BAD HEATER ELEMENT. REMOVED AND REPLACED L1 WINDOW, REF B737-800 AMM 56-11-11-000-801/-400-801. ACCOMPLISHED L1 WINDOW RESISTANCE TAP REF B737-800 AMM 56-11-11.