cableform eh?
are you sure its not just a cableform contactor array?
not aware of any lifttruck controllers made by cableform.
it might be curtis or GE, those are the only 2 controllers i've known clark to use, possibly a sevcon or danaher. I could be mistaken though.

but all that aside
generally if you get motor operation when 1A is pressed that verifies the motor is ok. From this point you need to check and make sure the contactors are actually making, check them for wear, dirty (carboned up) contacts, pitted contacts, binding armature on movable arm. Also check drive fuses on contactor panel on bus bars, check bus bars for loose burned (melted) connections.