As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EMERGENCY LIGHTS WOULD NOT COME ON. PER WD 33-50-50, PERFORMED ELECTRICAL WIRE TEST IAW EMB 135 WD 20-20-03. FOUND GOOD VOLTAGE AND CONTINUITY ON CONNECTORS FOR BATTERIES AND INVERTER. THE GROUNDING WAS POOR. CLEANED GROUND GS0580C. LIGHTING SYSTEM OPS CHECKS GOOD.