John Deere 1010

I have a 1963 John Deere 4 cylinder gas with a starting problem. I have replaced the ignition switch. When I replaced the switch, it started right away. I cut it off and it would start no more. I noticed that the coil or resistor on back of the switch was getting hot when I tried to start the tractor for a couple of minutes. This starting problem has been going on for a couple of months. One time it will start and the next time it will not. I had already replaced the sediment bowl because of a leak that I could not get stopped. Before I replaced the switch, it would crank and run as long as I kept the ignition switch held close to the start position, but when I released the switch to the run position, it would cut off. I am not sure of the function of the coil or resistor on back of the ignition switch, but I was concerned that it was getting hot after trying to start the tractor for a couple of minutes! Help Dennis Williams

James, the resistor on the back of the ignition switch limits primary ignition current to a value that's safe for the breaker points and coil. (Ignition resistor/ballast resistor.)

By the nature of what they do (RESIST the flow of current) resistors typically get HOT in use.

Of course, if there's a short of some sort in the primary ignition circuit it will get even HOTTER.

Start by checking for spark at the sparkplugs with a gap-type spark tester, and check back with us.

The manual at the link below describes how the primary resistor works, and how it is bypassed during cranking. The resistor is cover on Page 34 (actual number on page, index calls it Page 35).

http://farmallcub.com/rudi_cub/www.cleancomputes.com/Cub/Blue%20Ribbon%20Service%20Manuals/GSS-1310%20Electrical/Page-34.jpg

Thanks, I did realize that the resistor was for current limiting. I was not sure if that resistor remained in the circuit at all times or if it was just in the circuit during starting. Also, where can I find a good schematic of the ignition circuit on this 1963 1010? Thank you!

Bob, I am not sure how to use that link you gave me, it did not seem to show me what I expected to see.

I had to break it down to get to it.

Search: http://farmallcub.com/rudi_cub/ . Rudi' Farmall Cubs will come up. Go there.

On that site you want: Blue Ribbon Service Manuals, Choose manual GSS-1310 Electrical. Choose Page 34.

The 1010 to serial number 51039, had an ignition resistor built onto the key switch. From serial number 51040, there is a resistance wire made as part of the harness. During cranking, the resistor is by-passed in the key switch, so that full battery voltage (the voltage during cranking will be less than 12 volts) is supplied to the coil. When the key switch is returned to "RUN",the resistor will limit the voltage supplied to the coil to about 1/2 of the battery voltage.

As to your problem, We are presuming that the battery is charged, the starter is in good shape, the contact points are good, the point gap is correct, your condenser is good, and your distributor shaft bushings are good.

If the tractor will start, but not keep running when the key switch is returned to the "RUN" position, you likely had a bad key switch. The fact that the tractor started and ran fine with the new key switch until you shut it off, and then would not "fire" even when cranking, may indicate a defective new key switch.
To find out if the problem is in the key switch or wiring, you will need a voltmeter to check volts at the coil with the key turned to "RUN", and during cranking. An analog voltmeter with a needle, may be more useful than a digital voltmeter during the cranking test, and testing while the tractor is running. With the key turned to "RUN", you should have about the same as battery voltage at the coil - with the points open. If the points are closed, you may not show any voltage at the coil -, since the points are providing a direct short to ground. While cranking, the voltage at the coil + should be at least 6 volts. If the tractor is running, you should have about 6 volts at the coil +.
If these voltages are OK, then your key switch and wiring are likely not the problem. If these voltages are not OK, check at the key switch for battery voltage at the "B" terminal with the key "OFF", battery voltage at "F" in "RUN" with the points open, at least 10 to 11 volts at "B" during cranking and at least 8 or 9 volts at the "F" terminal while cranking. If you have battery voltage at "B" but incorrect voltages at "F", I would suspect a defective key switch. If the voltage at "B" during cranking is low, I would suspect poor battery cable connections or bad wiring.
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