[moosejaw]

Just remembered....

Check for a broken but not blown fusible link. Check all the wiring at the starter relay distribution. Another car (a taurus) had a fatigued and broken fuse link that would go intermitent at the worst times! Pull lightly on the wiring to see if a break is present. The sleeve over the link will stretch if broken. It should not stretch at all.

If the inertia switch is under the dash and the relay under the seat then it would make sense that the inertia switch comes first in the circuit.

Mike