# Ford 4000 starting problem



## Reet (Oct 19, 2020)

Help.......I have a 1972 3 cyl gas that won't stay running. It turns over & starts but once I release the key it quits. I changed the generator regulator (and polarized it). Still the same. Odd part is that if I bang on the generator it starts, well did twice anyway.
I'm stumped. It had been running fine.


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## the key of knowledge (Jul 12, 2020)

This was a common problem with early ford cars. The ignition was designed for 6 volt and the car had a 12 volt battery. A resistor was placed between the battery and the coil to reduce the voltage. When starting the resistor was bypassed giving max power to the plugs for better starting. If the resistor burned out then the car would start when the key was in the start position but as soon as it was released the engine would die because there was no power through the resistor. Some used a ceramic resistor while others used an wire that had the resistance built into the wire. Just take a 12 volt test light and test the B+ terminal at the coil. If no power with key on find the resistor and test both sides. If power on one side but none on the other side the resistor is bad. The problem could also be the ignition switch. Again use the test light and check both terminals of the switch; the one going to the starter in the start position and the other when the key is on for the run position.


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## Hacke (Feb 22, 2011)

Are the gauges and warning lamps working when the key is in ignition position?
Are the gauges working when you release the key (back to ignition position) after a starting attempt?
If yes on both, the key switch is OK.

Put a jumper wire from battery (+) to ignition coil (+) and do a starting attempt. If it starts, the key switch and/or the wiring/connections from key switch to the coil are bad. Remove the jumper wire.

Wiring diagrams:
https://www.tractorforum.com/manuals/ford-1000-series-1-65-12-74-wiring-info.13/


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## Reet (Oct 19, 2020)

Thank you I'll try it


the key of knowledge said:


> This was a common problem with early ford cars. The ignition was designed for 6 volt and the car had a 12 volt battery. A resistor was placed between the battery and the coil to reduce the voltage. When starting the resistor was bypassed giving max power to the plugs for better starting. If the resistor burned out then the car would start when the key was in the start position but as soon as it was released the engine would die because there was no power through the resistor. Some used a ceramic resistor while others used an wire that had the resistance built into the wire. Just take a 12 volt test light and test the B+ terminal at the coil. If no power with key on find the resistor and test both sides. If power on one side but none on the other side the resistor is bad. The problem could also be the ignition switch. Again use the test light and check both terminals of the switch; the one going to the starter in the start position and the other when the key is on for the run position.


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## Reet (Oct 19, 2020)

Hacke said:


> Are the gauges and warning lamps working when the key is in ignition position?
> Are the gauges working when you release the key (back to ignition position) after a starting attempt?
> If yes on both, the key switch is OK.
> 
> ...


Thank you


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## Ed Williams (Jun 13, 2019)

Also check if the coil is getting hot. Not likely if you cannot get it running, but a hot coil also indicates a bad resister. Check the resistance between the A and B posts on the coil. It should be between 3.5 and 4 ohms if the ignition system is wired with the correct resistance. Higher resistance will cause hard starting. Lower resistance will fry the points in short order.


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## JES2 (Feb 8, 2018)

Those models have a start and run type solenoid. When you crank the engine it gives the coil 12 volts. When it starts you let go of the key and it will go back to run. In your case it stops running. Check ignition and contacts. Also if you replace these solenoids they have to have a good ground where they mount.


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