Compressor cycles on and off

if pressures are good and system is cooling stat probe in the evaporator is cycling. stat switch prevents the evaporator from freezing into a solid block of ice reducing air flow. Switch is located on the lower left side of the air box and has a temp probe going into the evaporator. What is the duct temp while cycling?
That makes sense, I'll have to get back to you on the duct temp, don't recall what it was. Is the stat accessible from outside the box or do I have to split it? My thanks to all who are trying to help!