As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OKC - ON FLIGHT 4188 EMERGENCY LIGHTS CYCLE ON AND OFF WITH THE SWITCH IN THE ARM POSITION. AIRCRAFT FERRIED FROM OKC TO DEN FOR REPAIRS. MAINTENANCE IN DEN REPLACED THE AC ESSENTIAL BUS SENSE RELAY (K135) ON PCB5 IN JUNCTION BOX 11. ALSO REPLACED BATTERY PACKS AS PACKS WERE DEPLETED DUE TO THE PROBLEM. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.