That grungy-looking braided strap attached to the lower starter stud needs to be trashed- - - -they have a nasty habit of developing a poor connection and/or corrosion between the braid and the sheet metal cover on both ends. Attach a #0 insulated battery cable to the same bolt and the negative battery post. Then either run a NEW braided strap, or a #6 or #8 wire from anywhere on the engine (like a side cover screw, for instance) to the frame, and another one from the engine to the cab sheet metal. Those smaller grounds serve to provide low resistance and low current grounds for stuff like lights and instruments, heater blower, electric wipers if equipped, etc.
The "I" terminal on the solenoid cover needs to be wired to the upstream side of the coil, opposite the wire that goes to the distributor. That big purple wire that's on there now should probably be attached to the small stud on the engine side of the solenoid- - - -the one marked "S" on the solenoid cover. That's assuming it's got voltage when the key is in the "start" position or the starter button is pushed- - - -whichever starting system you have.
Jerry
