I had recently installed a mini starter in the Willys.

I had to install an internal shim as well.

All was good until weeks later with occasional no action

from the starter button.

I replaced the starter button, didn't solve the problem.

So, it had to be the wiring, a kink somewhere or...

off to the store, bought a roll of 10 gauge [replacing the 12 g.]

new wire ends, etc.

I have a tach sending unit mounted on the firewall with the 4 wires 

running through a grommet to the interior so I drilled the firewall hole

out larger and made a new larger grommet so I could run the starter

button wiring through it as well.

This made the wiring too close to the engine so I made a bracket

and mounted it to the valve cover, using another small grommet.

See attached.