Flexicoil mechanical cart problem

Hi, tried to calibrate meters on flexicoil 3850 mechanical cart, with the main clutch turned off and the 3 tanks turned on. Cannot get the main crank handle to turn past a half turn. I've turned all the individual rollers by hand, they are all free. Starting to wonder if maybe its a problem with the main clutch, as if its not letting go and I'm trying to turn the big rear wheel of the cart?... When the master switch is cycled you can hear it clicking, so it cant be an electrical problem... Day's been too long and my brain is gone numb. Anybody have this problem before? Thanks in advance for any pointers. Haven't hooked an ohm meter up to the wires yet, will try that next. What should a normal ohm reading be on the wires of the main clutch? Unit has been sitting for a couple days, but everything was working fine when I finished the last field...