1970 Ford Mach 1 Mustang with 351 Windsor engine, ignition solenoid wiring ?

[JimPghPA]

I have a friend who stores a 1970 Mach 1 with the 351 Windsor and he recently replaced the ignition solenoid. Now it starts up much better, but it will not shut off unless he disconnects the battery.

He knows that the after market parts are made for several years and also knows that sometimes these parts can have a problem with them.

1) Does anyone have an idea of what he should first check to correct this problem so it will shut off with the key?

2) Does anyone have a wiring schematic for the connections of the ignition solenoid for this engine in this vehicle?

Thanks in advance for any information that might solve this problem.

 

[clinebarger]

You mean Starter Solenoid? Fords with Points style ignition had a wire connected to the Starter Solenoid that would supply 12vdc to the coil during cranking. The terminal would be labeled "I".

Disconnect that wire....There should ONLY be power to the "I" terminal while cranking.

 

[JimPghPA]

I'm not a Ford person, and was not there when this work was done. He called it ignition solenoid, but it probably is the starter solenoid.

Thanks clinebarger.

 

[Lubener]

Are you saying it won't stop cranking or running without disconnecting the battery? Saying it won't shut off is very vague. There is no "ignition" solenoid.

 

[BigCahuna]

Luckily for your friend, the ignition system on a 1970 Ford is about as simple as it gets. What it sounds like to me is, he replaced the starter solenoid and that the engine starts. When he turns the car on, it doesn't want to turn off. What that also sounds like is, the 12 volts that feeds the ignition is still "on" when the key is turned off. Unless he switched wiring around, the key switch is still supplying 12volts, when it shouldn't. The key switch may be the culprit, if the wiring hasn't been switched around.,

 

[wag123]

Tell your friend to replace the "new" starter solenoid. Purchase a different brand from a different place. I have personally run across new ones that were bad right out of the box.

 

[mk378]

There are different forms of the Ford starter solenoid which look practically the same outside but are wired differently inside.

As @clinebarger said this is probably due to having the I wire, which is supposed to send extra voltage to the coil during cranking, miswired so it gets battery power all the time.