What is this ceramic thing on my coil?

A

allenlook

501 Club
I bought all new plugs, wires, dist. cap, rotor, condensor, points, etc. and started to put them on the tractor today. Well, almost. I shined up the starter face and it helped a lot as well as shining up the ground cables etc., but there was a lot of frying and sparking and zapping inside the new starter switch I bought, and I imagine it probably now looks like the old one, eg. black and partially melted!

I took off the coil and noticed I didn't have a recognizable condensor on it like on my Cub. That is, assuming I'm correct in assuming that little silver cylinder is the condensor... In its place was this little ceramic block, approximately 1 inch longer than the silver cylinder type and under which there was a wire-wrapped fiberglass element burned in half and corroded near one end.

This thing had wires connected at both ends, one coming from the coil and the others passing on I think to the solenoid on the fuel line and the other up into the dash somewhere (sorry it was getting dark and I couldn't tell exactly where in all that schmoo it was going.)

Any idea what this is, and why I don't have a little silver cylinder on there, and what the heck do I do now?

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OK BigDog, I believe you... I still don't know what to do with it :D

Do I replace it in kind, do I replace it with a newfangled device, or do I leave it out? Do I still install the condensor?

I'm afraid this is my first excursion into the electrical side of the tractor.
 
A balast resister gives a voltage drop from 12 volts to 6 volts. The coil you have needs 6 volts. You have a 12 volt battery there fore a dropping resister.

bill
 
Allen, that ballast resistor looks like the one I had on a 1955 Packard. It was bypassed when starting the car, and then in play when the ignition switch was in the run position. Reduced the voltage back to 6 volts for the ignition system. I think you definitely need the resistor and should replace it. There may be a resistance value marked on the shell. . Bill
 
Yep, this is a 12V system (battery at least is 12V), and I've bought a new 12V coil for the tractor.

The starter is 6V but I don't think that's a problem using it with 12V...

Will everything else in the system be OK if I leave this out and put in the new 12V coil?
 
A 12V coil is a 12V coil. It's got to have a built-in resistor, or it needs to be wound for 12V. Either way, putting in an extra ballast resistor would make the spark weak.
 
I put the coil on today, and it says right on the side of it, "12V, No External Resistor Required", and everything's working great. :)
 
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.

Eugene
 
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 :D
 
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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