1940 Special solenoid relay switch

[Business_As_Usual]

The contacts in the relay shut when we try to start the car. The solenoid does not respond. Checked it out on the bench, and when I grounded the unit on the connector that would go to the control box and ultimately to the generator and added 6 volts to the positive, the solenoid did not respond. Original problem was the car would not stop cranking with the key in the off position. I’m suspecting a bad relay switch. Does anyone know of a source to replace the switch. I would also like to know if a starter out of a 41 super would be the same as my 40 Special.  Also, would the fuel pumps be the same?  Both have 248 eng.  My car went into services in November 39’, if that makes a difference. Thanks, Tom

[Bloo]

That screams bad ground. Was it working before? How does your engine block ground to the battery? Could the starter be not grounding because of paint? Could the solenoid not be grounding because of paint?

 

The relay is a simple relay. If it is clicking down that's half the battle. It has a floating coil. Hot 6v is provided by the throttle/vacuum switch(es). Ground is provided by the charging system. All good so far if it clicks down.

 

That relay has points inside that COULD cause your issue. I would check other stuff first.

 

What the relay does is it takes hot 6v that it gets from the battery cable post of the solenoid, and connects that 6v to the solenoid coils (small solenoid post). You could jumper that manually to check. The solenoid should pull in, kick the copper disc at the back of the solenoid, and spin the starter. If it won't pull in either the solenoid windings are bad, or it doesn't have a ground.

 

If the solenoid and starter work when you jumper that, the most likely thing is dirty points in the relay.

 

Use a nice fully charged battery to test.

 

 

[Rock10]

If the switch was stuck on, it could have burnt out the coil in the solenoid.

[Rock10]

I think this is right: with the switch on the bench, apply voltage to the big terminal and ground the case. Then apply with a jumper voltage to the terminal that had the black wire on it.

The magnet should energize and pull the plunger in. Releasing the small terminal should let it pop back.