As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
POINTS IN RELAY FUSE TOGETHER CAUSING RUNAWAY TRIM ACTION RESULTING IN UNCONTROLLED ATTITUDES OF AIRCRAFT. REQUIRES BOTH PILOTS ON CYCLIC TO OVERRIDE. RELAY MFG HAS INDICATED THIS IS NOT THE CORRECT RELAY FOR THIS APPLICATION. INSTALLED NEW RELAY PER MM.