Seneca II landing gear
My 1976 Seneca II will intermittently fail to complete the retraction cycle after takeoff. Selecting "Gear UP" will begin the cycle by extinguishing the three GREEN down lights, illuminating the red UNSAFE light, electric motor engages and draws power(ammeter reading increases). After 30 seconds, I have recycled to GEAR DOWN, and gotten 3 GREEN lights. Then usually, the second GEAR UP selection will finish normally, and red UNSAFE light goes out. Mechanic unable to duplicate this on jacks and gear swings. All is normal on jacks. Microswitches have been checked, and continuity seems ok. Asking for solutions, comments from experience with this problem, and how to fix it. This problem has plagued me ever 3-4 months, regardless of weather (airplane is hangared) ever since plane was purchased in 2007.