no start after sitting

Starter relays are simple. The "big stud" is a junction point AND one contact. The big "Square" terminal is the other contact and feeds power down to the starter

The two flag "push on" terminals are the relay coil, the electromagnet

The functional path is ignition switch--- YELLOW start wire---through the bulkhead connector---to one of the relay push on terminals..........through the relay coil........down to the transmission.......to the neutral safety switch center terminal

(The outer terminals on a 3 pin NSS are the backup light switch)

Wiggle/ move the shifter while twisting the key to start. Any click or try to crank indicates either a bad switch, mis--adjusted linkage, or sometimes a problem with the "rooster comb" in the transmission

YOU NEED to get a test light, multimeter, and some alligator clip leads so you can do testing.

"Rig" a test light or meter onto the yellow start wire connection. Do this WITHOUT disconnecting from the relay. Twist the key, see if you have voltage.

If you do have voltage, and it won't click, or crank...........

Now move to the wire going to the NSS. Twist the key, see if you have voltage. You should not. With the transmission in N or P the switch should be ground.

If both these check out and it won't crank it is likely the relay. You can make a final check

Take a clip lead or even screwdriver. Jumper from the big stud to the terminal of the relay that was connected to the yellow. If it does not crank, pull the NSS wire off, and ground that terminal with a jumper wire. Again jumper 12V to the first terminal. IN other words, you ground either flag terminal, and connect 12V to the remaining one. DOES NOT MATTER which is which. If it will not crank,

Try jumpering across the big stud and the big square screw. If it does crank, replace the relay