'93 240 electrical gremlin...help!

The car runs great. But every now and then, with no rhyme or reason,
it will not restart after you shut it down, like at the store, gas
pump, wherever it is most inconvenient. The starter won't crank, all
lights work, dash lights, etc., just like no power to the starter.
Then after sitting a while, usually half an hour or so, it will turn
over and start fine. The starter has been replaced. There was an
after market alarm which has been disconnected, thinking it was
related to an ignition lock out. Of course, the shop can't diagnose it
because it doesn't do this while they have it.
What stumps me is why is it ok after it sits a while if it is
electrical?
Help!
Craig

 

When it happens, you need to see if there's power getting to the
switched terminal (small wire) on the starter motor. First try neutral
instead of park if the transmission is automatic. There's an test lead
up on the firewall near the center of the car that's a remote starter
wire. See if power's getting there. If not, check at the ignition
switch, this is before the neutral switch, so that won't have any
effect. If there is power, see if the power gets to the small wire on
the starter.

 

Relays can become temp sensitive,will not actuate till cool.