What was found
ON SHORT FINAL THE FADEC CHANNEL FAIL CAUTION LIGHT ILLUMINATED; IT WAS FOLLOWED BY THE CHECK INSTRUMENT WARNING LIGHT A SECOND LATER, THEN FINALLY THE FADEC MAINTENANCE LIGHT CAME ON FOLLOWED BY A MARRIED LOSS OF MY NR AND NP NEEDLES. MUCH LIKE A BIT TEST THEY DROPPED TO ZERO MOMENTARILY AND THEN CAME BACK TO 100%. THERE WERE NO SECONDARY INDICATIONS OF ROTOR RPM OR ENGINE RPM CHANGE. ONCE THE NR AND NP NEEDLES WERE BACK IN THE GREEN THE FADEC MAINTENANCE LIGHT EXTINGUISHED. I DID NOT PERFORM THE EMERGENCY PROCEDURE OF RESETTING THE FADEC AS I WAS ON SHORT FINAL WITH A SAFE LZ BELOW. I FELT IT MORE PRUDENT TO CONTINUE THE STABLE APPROACH. REPLACED THE HARNESS.