WOW! I just found the problem that had had me going all weekend, and it has reminded me that it's a mistake to just ASSume that a component is at fault without carrying out the proper troubleshooting procedure.
It turns out that the source of my intermittent starter failure was not the relay as I had suspected but some mickey-mouse wiring repairs by a previous owner, Mr. Scotchlock. This owner didn't like to make proper electrical connections and relied on Scotchlock connectors, which join two wires by clamping the two together and make a connection by cutting the insulation. Of course, this weakens the wires and becomes a failure waiting to happen. I had previously found failed Scotchlocks on the taillight wiring and found no fewer than 5 on the wire going to the ignition coil. This time I discovered 3 on the red/white wire leading from the ignition switch to the starter relay via the interlock module (strange thing that)
When I troublshooted (troubleshot?) the circuit with a test light the problem revealed itself quickly and by removing the Scotchlocks and repairing the damaged wires the problem was solved and I now have a car that starts...every time I turn the key.
Cheers,
Rich
BTW: MY apologies to the late Mr. Jos. Lucas for the names I called him [:I] , and brickbats to Mr. Scotchlock, whoever he may be![:(!]
1975 TR7 ACL764U
