HOW TO OPERATE 259E SKID STEER AFTER REMOVING FRONT DOOR.
You may need a jumper plug for the wiring, the newer unit Sr series have a plug that gets disconnected and a jumper the plugs in to end to bypass the door safeties that are in place so as the unit cannot move with the door open.
The 259D needs a jumper to operate without a door. See here HeavyEquipmentForums