all the NSS does is complete the ground circuit to the starter relay, allowing the relay to energize the starter circuit.
i
f it starts in neutral but not in park, the switch is good.t[u]hat leaves only the linkage adjustment or the rooster comb as problem areas to address.[/u]
the NSS may need to be tightened a little more, or the wiring inspected to be sure the shift linkage is not inadvertently "moving" the plug a little. that tidbit cost me more than a few hairs to be lost before discovering that.
With what he and others are saying
The switch doesn't know or care what position the shifter is in only that the contact point is depressed or touching the rooster comb to ground the signal wire. There are different rooster combs as well.
tightening the switch as MOPARX suggested and if possible may do the trick. The attached pic is a generic 727 valve Body but shows the two points that ground / depress the contact.
Second pic is of a 3 pin NSS with the center pin being the contact point.
