Farmall Super A, AV, 1939 - 1954
Moderator: Team Cub
It's a ballast resistor, also called a voltage drop.
What the heck do you do now? Allen you need to follow the wires coming and going from the resistor. If one leads goes to the electric fuel shut off on the fuel line, then the fuel shut off operates on 6 volts.
My guess is that one wire is connected to the ignition switch - hot in on only position.
Since the resistor gets hot, it works. If the fuel shut off works, you need to leave the resistor in the system.
I assumed from Allen's description that the wire to the fuel shut off was on the ignition switch end of the ballast resistor. If so, that lug is just being used as a junction point to feed 12 volts to the shut off. If it is on the coil end of the resistor, then the fuel shutoff is running on 6 volts. If so, and if the ballast resistor is only used to power the shut off, it probably will not reduce the voltage to anywhere near 6 volts but remain closer to 12.
You are correct Jim, the fuel shutoff solenoid was attached to the end of the ballast resistor only because there was a spade lug there (two or three of them actually.) It was attached on the ignition-switch side of the resistor.
I have connected it to a new spade lug directly on the coil, and it seems to be working fine. Unfortunately it was spray-painted so I can't read anything on the labels, but I will double check today and see if I am overfeeding it.
The ballast resistor was blackened and burnt in half near one end, and while the wiring may still have been connected somehow, it was very rusty and I think the resistor was pretty much worthless. Now that I have a coil that says it does not require an external resistor, I'm assuming that I'm OK feeding everything the way I am - but what the heck do I know.
On the bright side, I sure am learning a lot
OK, I've got everything wired correctly as far as I can tell - and still no shut-off - the lamp stays lit the entire time, although if I disconnect it the engine shuts off...
Maybe I have too large a lamp or something, but anyway, I'm going to Radio Shack this afternoon and getting me a diode. That should take care of it, yes?
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