farmall 130 no start

My farmall 130 will not start.Checked for fuel and carburator and seems ok.It ran perfectly one day and the next would not start.Checked spark very little with tester.It has electronic ignition.Can these suddenly go bad?I replaced the coil with one I knew was good.No difference.I also replaced the distributor cap and rotor.This tractor always started and ran like a top before.It's also been converted to 12 volts so spins over great.It did run for just a few seconds twice and then quit.

Thanks for any advice or suggestions.

yes electronic ones will go bad suddenly, usually no spark at all. Check all your connections are clean and bright.

Could be as simple as a poor connection or a bad switch or the electronics has gone bad. Easy way to test is to run a hot wire fro mthe ignition side of the battery to the ignition side of the coil. If it run that way then the ignition switch or a connection or even a wire is bad

Does your 12 volt conversion have a 12 v coil or a 6v coil with a resistor. Resistors go bad, one minute they work, the next minute they don't.

Didn't see you had electronic ignition. I don't know if those use a resistor.

First, check for spark at the coil tower. Should give a 1/2-3/4" blue spark. If good there, something is wrong with the spark delivery. Even with new cap and rotor, it's aftermarket, anything is possible.

To check the ignition, disconnect the wire from the distributor side of the coil, ground the coil terminal with a jumper wire.

Turn the ignition switch on, read the voltage on the ignition side of the coil.

If it has a resistor, should be around 6 volts, if no resistor near battery voltage. Try cycling the ignition switch several times, be sure the voltage is steady and only drops when the switch is off.

Reconnect the distributor side wire. Connect a test light or analog volt meter from the distributor side coil terminal to ground, spin the engine through. The light should flash or the meter drop each time the electronic switch closes and opens.

If no light or voltage, there is a short in the ignition module or the wiring between the module and the coil.

If the light stays on steady, or the voltage stays high, the module is open or the wiring between the module and coil is open, or the module has lost it's ground.

If the light only dims, or the voltage doesn't drop to zero, the module is failing or has a weak ground. Seldom will a module fail, usually work or don't.

Be sure the trigger is in place, and the distributor is turning.

There is also a separate power supply to the module. Be sure it is getting battery voltage anytime the ignition is on.

If this is a Pertronix they have good customer service and troubleshooting.

If the light only dims, or the voltage doesn't drop to zero

The module does not pull to a true 0V ground the voltage reading will be about .5V . I doubt you will ever see 1/2V on an analog meter very close to 0 is close enoufh if it switches more than likely its good.

A logic probe would be a good cheap tool to confirm switching... :wink: