OK, we're interchanging the word "relay" with the word "solenoid"....the ISO relay in my drawing will be added to the start circuit and energizes the existing Ford solenoid. The ISO relay is available from many sources, just ask for a "30 Amp ISO Relay"....most come with the connector and short pigtail wires.

The solenoid I'm referring to is the existing Ford firewall solenoid; the existing wire that now goes from the Start button to the solenoid "S" terminal is interrupted by the ISO relay in my schematic I.E. the existing wire goes to terminal 86 and jumpers across to 87. The wire from ISO terminal 30 goes to the "S" terminal on the existing solenoid and terminal 85 goes to the center pin on the NSS. This way the starter will only be powered in Park and Neutral by a ground from the NSS.

As before, in order to use the Ford solenoid with the Mopar starter you will need a jumper between the two terminals on the Mopar starter; this is assuming you are powering the Mopar starter large terminal from the Ford solenoid large output terminal.

But if you are hooking the battery positive cable directly to the starter and using the Ford solenoid only as a relay, no jumper is needed and the output side of the solenoid would go to the small "S" terminal on the Mopar starter.

Confused yet?