Wiring Diagram For 3930 Ford Tractor
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Discussion Starter · #1 ·
Please help. Last year I replaced my Ingnition switch on my Ford 3930 tractor. I seem to be having the same problem again. I turn the key and the dash lights come on. and nothing else happens. The statrter is good. I can start it with direct wire on the starter. Can I test the switch??? I have heard there are safety switches that also come into play ( relay switches i guess) also.
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Can you start it by using a jumper wire from the battery to the small terminal of the solenoid? If not, the solenoid may be bad, or not making a good connection.
If you can start it that way, the problem is likely in the switch or switch wiring.
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It will have a neutral safety where the range lever must be in neutral for the tractor to start. Might have one for the tranny and or clutch too. Never had a 3930 but they're just modern 4000's. Look on the right hand side of the tranny there should be (if it's like the Fords I've had/have) two wires going to a disc shaped switch. If you pull them off and jump them you can bypass to test. Just be sure its in neutral and you're on the tractor. It's just a switch that's closed when the range lever is in N (you can try just wiggling the range lever first within the N position) Replace the switch, if its faulty; it's there for a reason.
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I believe my 3910 has a switch on the clutch as well as the neutral lever. My solenoid for the starter does not last if I leave the tractor unused for any duration. I have replaced the starter solenoid twiced. Appears the innards corrode.
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Discussion Starter · #5 ·
I can jump start it by using the starter solenoid So I will check the other switch's tomorrow thanks for the locations . I will report back.
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Discussion Starter · #6 ·
I disconnected the Nuetral/safety and connected the two wires together still no luck. I also checked the fuse box. Like I said I can touch the Pos. on the starter and the nut and start it that a way..
But Iddee Can you start it by using a jumper wire from the battery to the small terminal of the solenoid? If not, the solenoid may be bad, or not making a good connection.
If you can start it that way, the problem is likely in the switch or switch wiring.
I asume touch pos on the battery with the jumper wire to the soleniod. Is that the same as when I jump it in the Statter?
Is there a way to test the Ingntion? witha muitimeter?
My Ignition has 4 wires hooked on it.
Or any other tries?
thnaks/
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If its a straight 8 speed then there is a nuetral safety switch under the shift cover on the high/low lever. If it has a shuttle trans then there might be a switch on the shuttle shift linkage.
Both 3930 and 4630 have a second switch on the pto lever also. Check the harness connections, check the relays and fuses in the box behind the battery. You may need to get a wiring diagram to track down such a problem.
Hintonlady's husband
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Get an automotive test light, attach the gator clip to the small wire that feeds the solenoid from the switch, ground the test light's point to the available metal. Turn the switch, if the light fails to come on, the problem is before the solenoid.
If the light does come on, replace the solenoid, assuming the starter does not respond. Every time you use a test light, first make sure its working via connecting to the battery posts. Either post will work when you cross test the battery, only the positive terminal will cause the light to respond when you ground to the available metal.
Some earlier tractors used a negative circuit, but I don't think thats what is an issue here. An auxiliary ground wire connected to the solenoid's mounting bolts, and then to the available metal, does assist preventing internal corrosion via static electricity.
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If you are able to start it by jumping the solenoid and you have power to it then you will need a new solenoid.
Source: https://www.homesteadingtoday.com/threads/ford-tractor.189490/
Posted by: blackcurrent10.blogspot.com