How do you test starter switch on firewall?

[Sonny]

My car will not start with a key. It only starts and runs by jumping the 2 studs with a screw driver.
obviously I meant “starter relay”. I also grounded the NSS and still no start so NSS is good.

 

[Don Frelier]

Try and jump the battery stud to the yellow wire terminal.
If it works then you have an ignition switch / bulkhead problem.
If it doesn't then the starter relay is bad.

 

[AR67GTX]

Try pulling and cleaning the bulkhead connection plugs at the firewall. The upper one is mostly windshield wiper but you will probably need to pull it first to get to the other two below it. The plugs have a plastic clip on each side that has to be pulled out to get the plug loose so don’t get too rough with them or the clips can break. As a quick test you can try wiggling them and pushing in on the plugs to see if the connection gets made. Same with the ignition switch - reach under the dash and push it in while wiggling it. If it starts by key then, you just need to clean up connections. If not you will need to start tracing circuits and testing for continuity and voltage.

 

[Don Frelier]

Try pulling and cleaning the bulkhead connection plugs at the firewall. The upper one is mostly windshield wiper but you will probably need to pull it first to get to the other two below it. The plugs have a plastic clip on each side that has to be pulled out to get the plug loose so don’t get too rough with them or the clips can break. As a quick test you can try wiggling them and pushing in on the plugs to see if the connection gets made. Same with the ignition switch - reach under the dash and push it in while wiggling it. If it starts by key then, you just need to clean up connections. If not you will need to start tracing circuits and testing for continuity and voltage.

Good advice but he may just have a bad relay.
Start with the easy stuff first.

 

[Moparguy59]

Good advice but he may just have a bad relay.
Start with the easy stuff first.

The body of the relay should be grounded

 

[R413]

The body of the relay should be grounded

This is false, no ground needed on the starter relay. The car will crank with the relay floating in mid air.

Don’t believe me, take one apart, nothing connected to the housing.

 

[Beekeeper]

This is false, no ground needed on the starter relay. The car will crank with the relay floating in mid air.

Don’t believe me, take one apart, nothing connected to the housing.[/QUOTE
View attachment 1188468

I think the M/T vs auto trans starter relay is the difference in the ground.

 

[R413]

Ok yes good catch. The 1969 and older MT gets the ground for that terminal from the body. The automatic gets the ground from the NSS.