Put a volt meter on the trigger post of your relay and have your wife hit the key. It may be poor connection anywhere between the battery - bulkhead - fuse box - ignition switch connector - ignition switch - ignition switch connector - bulkhead - starter relay (including the bulkhead connector at the firewall); or a defective ignition switch. If you don't get the battery volt signal from the switch (at the relay), check the output of the switch (at the switch) when you hit Crank. If still nothing, make sure you have battery voltage going in. A poor connection somewhere between the battery & switch will often show voltage until you hit Crank; at which time the volts will drop to practically zero. Yea, yea, I know, a lot of work; but that's why most folks hate electrical issues.
