bad starter relay?

HOW THIS WORKS

The great big stud hooks to battery and is one of the contacts. It ALWAYS has power and IS NOT fused

The other big bare "square" contact leads down to the starter solenoid,and is the other relay contact. It should be "hot" when starting

Either one of the small "push on" flag terminals goes to the yellowish (most years) "start" wire. This is hot when the key is twisted to "start."

The remaining small flag terminal goes to the clutch switch (stick car) or the neutral safety switch (automatic)

That remaining terminal is grounded by the neutral switch in park or neutral, or by the clutch switch when it is depressed.

The two small flag terminals are the relay magnetic coil

HOW TO TROUBLESHOOT

Find the "start" wire. Clip a light or meter to it and twist key to start. Should get battery voltage when doing so. If starter will not engage..........

Clip your meter to the big square terminal. Should have battery voltage when key in start if not........

Wiggle the shifter through park/ neutral and see if you get a click or two. If not, move your meter to the flag terminal leading to the neutral safety switch. Backprobe the connector, do not disconnect anything. This should NOT show voltage when cranking. If it does, there is problems with that wire, or the neutral safety switch or it's adjustment or the shifter linkage.

If this shows nothing, you likely have a bad relay

FURTHER

Sometimes it is simpler to .............

Use pliers/ screwdriver/ coin to jumper across the big stud and big square terminal. MAKE CERTAIN transmission is in neutral or park. It should crank.

Use a test clip lead(s). Disconnect both small flag terminals. Clip a wire to that terminal and clip other end to ground. Jumper from battery power to the remaining small flag terminal Starter should engage. If not the relay is bad