As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT AC GEN LIGHT ILLUMINATED. RAN ORH LIGHT WENT OUT AND RE-ILLUMINATED. RETURNED TO DTW. TROUBLESHOT WITH LINE MAINTENANCE AND APPEARS TO BE BAD GCU. MX REMOVED LT GEN CANNON PLUGS, CLEANED AND RESECURED. REMOVED LT GCU CANNON PLUG, CLEANED AND RESECURED. RAN A/C FOR 30 MIN. FOUND NO FAULT LIGHT ILLUMINATING. ALL CHECKS GOOD.