Heat Pumps and Electric Heating - Hard start kits

I have an inquiry about Hard Start kits...I posted last year and am still having issues with my Heat Pump..first I thought the defrost board was bad..nope! had a Tech come out for a "Free" diagnosis....he checked wires and t-stat...figures the reversing valve is "hanging up".....thats where it ended..well with heating season upon us again I am having the same problem....the Heat Pump runs fine....80% of the time when it switches over for defrost it sounds as if the compressor is trying turn over..the lights dim in the house after 5-6 attempts trying run it goes..it defrosts and goes into it normal operation until it decides randomly when to act up in defrost...it ran fine this summer in A/C mode....but then again it wasn`t reversing itself....is it something that I can correct with a Hard Start Kit...is it trying to defrost when the compressor still has to much head pressure? It`s a 5 -6 year old Armstrong Air Concept 1000 (10 Seer) with a Armstrong Air handler/electric furnace in basement..i`m in Ontario Canada right off the shore off Lake Ontario. :confused: