Ford 8N Electrical issue

[cladwig]

Looking for some help. I am trying to restore my grandfathers Ford 8N. I have a couple questions for the group.

1. Tractor turns over with the key on or off. Any suggestions?
2. I have constant power to the alternator with the key on or off. Normal or not? I don't think it should.
3. I have no power to the coil(front mounted distributer). Traced back and replaced key switch as it was faulty. Replaced resistor because I only had power on one side. After replacing, I still have power only on one side (when I turn key on). Any thoughts?

Thanks for any help you can share.

 

[HFJ]

1. the switch only switches ignition current. the tractor should turn over regardless of that switch being on or off. this assumes the 8n has not been retrofitted with an automotive ignition setup. is your switch simply on/off?

2. this is normal. again, that's something that is not routed thru the switch.

3. a wire should connect from battery hot (it sounds like u have 12 volt negative ground, if so, from battery +) to the stud on the OEM resistor which is by itself, farthest from the resistor coil. from there, another wire should go to one side of switch, other side of switch connects to one of the 2 studs nearest to resistor. wire from last stud goes to coil.

 

[cladwig]

Only a 6 v system if that maters.

 

[HFJ]

it doesn't affect the wire routing or the behavior of the ignition switch. is that a 6 volt alternator? is your system still positive ground?

 

[HFJ]

more accurately, i should have said it doesn't affect wire routing with the exception of which battery post connects to the bottom stud on the resistor assembly.

 

[Tim PloughNman Daley]

Glad you are inheriting grandpa's 8N. It sounds like your wiring is all mucked up. You said "I have constant power to the alternator" then say it is 6V. First, disconnect the battery, determine if it is 6V or 12V, and take to a local shop to get tested. If bad you need to get a good brand new one but verify what voltage you want to use; the OEM system is 6V/POS GRN. A 12V switch over is best done with a 12V battery and alternator. The 6V system was designed with a generator and voltage regulator. When doing a 12V switch over, the genny and VR are taken out of the circuit. Both systems will still use the OEM Ballast Resistor on back of dash. The front mount distributor has an OEM 6V coil. A 12V switch over job requires that an external 1-OHM resistor be added into the circuit. How are you testing circuits -with a VOM or test light? You will need to verify all wiring is correct before connecting a battery and applying power. Here's the OEM 6V/POS GRN electrical diagrams. Your local starter shop can bench test the battery, starter, generator or alternator, switch, AMMETER, and VR. The coil can be tested static via a VOM but requires very sophisticated and expensive equipment to test fully, so if static passes, use it. Don't go buying new parts until old are determined to be defective. FORD components were engineered to be rebuilt over and over. The OEM generator, starter, distributor, carb, governor, water pump, hydraulic pump, and more are the first choice if detected to be non working. I'd leave coil and distributor alone for now. The front mount is only mounted one correct way and if it is off, will destroy the base of the unit. Take baby steps - one step at a time. Remove battery and get tested. Disconnect any lights. Lights were never a factory item and often are wired wrong. Get wiring verified first -use a VOM set to continuity, note a test light. Don't go by wire colors - colors don't conduct electrons. The Essential Owner/Operator/Parts/Service Manuals are important tools to have.

CORRECT FORD 8N ELECTRICAL SYSTEMS - 6V & 12V:

*PICTOGRAMS courtesy of JMOR

FORD 8N TRACTOR WIRING DIAGRAMS:
PRIOR TO S/N 8N-263844:

FORD OEM BALLAST RESISTOR -USED ONLY WITH FRONT MOUNT DISTRIBUTOR:

EXTERNAL 1-OHM CERAMIC RESISTOR - USED ON FRONT MOUNT AND
ONLY IF COIL IS 6V:

FORD 8N TRACTOR ESSENTIAL OWNER/OPERATOR/PARTS/SERVICE MANUALS:

Tim Daley(MI)

 

[Jim L WA]

Are you calling the generator an alternator? That might clear things up. Also are you using a volt meter to trace battery or a test light. If you have one, take actual volts readings on both sides of the resistor and report back to us.

 

[cladwig]

Thank you for all the help!! It was very much appreciated. Actually got the tractor to start and run last night after not running for 20 years. It turns out my spark issue to the coil ended up being rusty washer and nuts on the resistor. I feel foolish, but I reused the washers and nuts onto the new resistor and that was my issue. Everything else seems to run as it should. Thanks again!!