[seamus2154]

I know we forget but our vehicles are 42 years old. If it is starting when you jump it the only thing you are cutting out of the equasion is the wiring, ignition switch, and key??? I would replace the ignition switch and check all the wiring from the starter back to the key. I have seen some starters not to work when hot because the solenoid needed shielding, but if it starts when you jump it I guess that rules that out. I don't know of a relay for the starter maybe someone can chime in.