Starting problem

I changed my ferguson to30 from a 6 volt to 12 volt system. It turns over, but will not fire. Any suggestions? Started up before I made the switch. I followed the wiring diagram that came with the kit from Yesterday's tractor. Thanks

Need to do some diagnostics.

Check for spark at the coil. Should pop a strong spark about 3/4" to ground. Then check for spark at each plug, should spark 1/4". If not, there is an ignition problem.

Do you have a test light or volt meter?

Check for voltage at the switch side of the coil to ground. If you kept the 6v coil and added the resistor, with the ignition switch on, you should get battery voltage with the points open, about 6v with the points closed.

If you get no voltage, or very low voltage, start checking back to the switch, amp meter, battery, until you find the power loss.

If you get good voltage at the coil, move the test light to the distributor side of the coil. Ignition switch on, you should get battery voltage with the points open, 0v with the points closed.


If the tests prove good, and still no spark, try a coil, different condenser. Be sure the points are making contact, are adjusted properly, the distributor shaft doesn't have excess side play. Be sure the battery is fully charged, especially if using the ignition resistor.

Steve has you covered on the diagnostics

What coil are you using? If using original 6 volt coil with resistor from the kit, I've seen several kits with resistors that were too high resistance. Resistor should equal resistance across + and - posts on the coil, about 1 1/2 ohms

If you replaced coil with "12 volt, no resistor required coil" and then added the kit resistor it will be hard to start.

You could jumper across the resistor and see if it improves starting. Won't hurt to run it for a short time.

If it now has alternator and negative ground, the -- on the coil goes to side of distributor

So since it now has the negative ground I should switch the wire on the coil To be opposite of what they were when I had the positive ground system?
This is a great site. A lot of great help. I appreciate it. I got this tractor from my 92 year old uncle last summer before he passed away last Fall. I am trying to keep the tractor in good shape in his memory.

[qruote="Steve@Advance"](quoted from post at 16:41:29 07/21/17) Need to do some diagnostics.
I got it running. Can I get a coil and condenser at any auto store? Is the ammeter gauge showing a high because I still have the 6 volt coil on without the resistor?
Check for spark at the coil. Should pop a strong spark about 3/4" to ground. Then check for spark at each plug, should spark 1/4". If not, there is an ignition problem.

Do you have a test light or volt meter?

Check for voltage at the switch side of the coil to ground. If you kept the 6v coil and added the resistor, with the ignition switch on, you should get battery voltage with the points open, about 6v with the points closed.

If you get no voltage, or very low voltage, start checking back to the switch, amp meter, battery, until you find the power loss.

If you get good voltage at the coil, move the test light to the distributor side of the coil. Ignition switch on, you should get battery voltage with the points open, 0v with the points closed.


If the tests prove good, and still no spark, try a coil, different condenser. Be sure the points are making contact, are adjusted properly, the distributor shaft doesn't have excess side play. Be sure the battery is fully charged, especially if using the ignition resistor.[/quote]

" Can I get a coil and condenser at any auto store? Is the ammeter gauge showing a high because I still have the 6 volt coil on without the resistor?"

I would get a direct 12 volt coil "12 volt, no external resistor required" and omit the resistor. One less part to give trouble in the future. NAPA IC14SB or equivalent coil

If it runs with the old condenser, don't replace it. Good chance a new condenser will be a dud

If ammeter showing high charge when running, the coil and/or resistor has nothing to do with charge system. Charge level should come down as battery charges.

Thanks Again.

I bought a new battery and charged it before putting it in the tractor. It seems odd that it would spike all the way to the negative when I turn on the key and all the way to the positive when running.