Coil with external ballast resistor issue

[pdwatts65]

I have a 76' IH Cub Longstripe and have and issue with it dying after it gets warmed up. After about 20 minutes into running, it will die, start right back up and then die again once I start driving. This continues to repeat until I let it cool completely down and then starts over. after warming up again. The coil is so hot I cannot put my hand on it so I changed the coil and the problem is still there.

So here are my questions:

1. Could the external ballast resistor be bad and cause this issue?

2. If so, should I change it? Or get a coil with and internal resistor and do away with the ballast resistor altogether?

3. If I get rid of the ballast resistor, what coil should I buy for it and what do I do with the wiring?

4. If I change just the ballast resistor, what is the part number or where can I find one?

Any help would be greatly appreciated.

[Slim140]

Your Cub should be 12V, why do you need a ballast resistor? You do have a 12V coil on it don't you?

[Jackel440]

Sounds like a bad ballast resistor.
I'm new to these lo boys but I use ballasts from a Chrysler on my big Farmalls for the coils. Now my 400 has an internally ballasts coil and it works great.

[pdwatts65]

It is 12 volt but for some reason there is a ballast resistor mounted next to it and the coil is without internal resistor type. This is how it was set up when I got it. I have a picture but the file is too large to load on here.

Just trying to figure out why the crazy thing keeps dying and was told it could be the coil but I replaced that already. So was thinking there may be a problem with this resistor???

[Slim140]

If you have 2 coils doing the same thing then I would say it's your resistor gone bad.

[pdwatts65]

Thanks for the information guys. Any idea where I might find a resistor? I see some on line that look like it but not sure 100% on what to buy. I don't have the tractor here to check for a part number as its at my ranch about 100 miles away. I usually try to have any parts I need when I go, small town and other than gas and chips, you have to bring it.

[Slim140]

TM Tractor (site sponsor) has a coil with internal resistor for $35.10
http://www.tmtractor.com/new/el/808fp.htm

[Eugene]

Any auto parts store. Ask for a Chrysler ballast resistor. The resistor Ohms won't make any difference. They will probably tell you they have two different resistors in Ohms.

Ballast resistors either work or they don't. I suspect you still have a bad coil. Even if it's new from the auto parts store, still could be faulty.

Edit. You could purchase a 12 volt coil with internal resistor and eliminate the ballast resistor. Again, from auto parts store.

2nd edit. You could swap coils from a running tractor and see what happens.

[pdwatts65]

I have a new coil already on it. Would it be better to just replace the resistor and stay with what I have? Or is there an advantage to changing the coil over to one that has internal resistor and take the resistor out of line?

[Eugene]

The ballast resistor is quite a bit cheaper than a coil.

There is no advantage of the ballast resistor and coil over a coil with the internal resistor.

[pdwatts65]

hmmmm....a bad NEW coil......didn't think about that. Unfortunately I don't have the benefit of have another running tractor to borrow one off of. So to replace it is just a basic 12V coil WITH resistor and then take the existing resistor out of the circuit?

[Eugene]

Since we are guessing, I would go with a 12 volt coil with internal resistor and remove the ballast resistor.

[pdwatts65]

So there is not anything specific about the coil.....just a basic 12 volt coil with int resistor.

Just need to remove the existing resistor.....

[outdoors4evr]

Completely your choice. Resistors very rarely fail as shorted. They normally fail to an open state. I would take the resistor out and measure it to see if it is still in tolerance. I would bet that the coil is bad and would replace the coil with a new 12V coil with the built in resistor. This is what your tractor was delivered with from the factory.

[pdwatts65]

Awesome! I was wondering why it has the external resistor. I will go to the auto parts and get on with internal resistor.