HiYa Ron-
You are asking and getting good advice from two of the most knowledgeable electrical experts on this forum -Soundguy and Bruce(VA)so take heed. By ?early 8N? we will assume you have a front mount distributor, and that is what matters for now. Equally important as well is we need to know if 6V or 12V. The original Ford electrical systems were 6-VOLTS/POSITIVE GROUND, all vehicles, not just the tractors. Many have been switched over to 12V/NEG GRN and there's nothing wrong with that. Either system requires it to be wired correctly and that is where many if not most problems occur. It sounds like you have some boogered up wiring so let?s go thru the basics. The early 8N setup required a 3-wire generator, a voltage regulator, a ballast resistor, an ammeter, starter switch button, 6V battery, 6V coil, an ignition switch, and all the wiring connected correctly. If you see a round-can unit on the rear dash/steering box, it is a cutout circuit ?used from post s/n 9N-12500 until the end of 2N production. It has 3-wires terminals. The 8N Voltage Regulator has 4 Wires, not 2. There is a terminal for: ARM; BAT; FLD; and a GRN terminal. The original 8N voltage regulators were supplied by AUTO-LITE (see picture), and as are all 8N VR?s mounted on the upper RH rear dash panel, near the oil pressure gauge. The newer aftermarket VR?s (see picture) are a bit different than the originals, but, still have 4-wire connections. If you have a VR, and only find two wires connected, I?d start there. You say you are using a VOM ?that?s good, a test light won?t tell you what you want to know, and most require power to be effective. A meter can be used as a continuity tester and requires no power to a circuit, but you are going to be working in DCV and OHMS (AMPERAGE). It is important that you have your VOM settings correct when checking either or. A dead battery isn?t going to help matters so first up is to get the battery tested and if it?s bad, replace it with the correct style. No Deep Cycle, RV, golf cart units ?GRP-1 6V, GRP 25 or 35 12V. The battery must sustain a full charge under load to be effective. A good starter/alternator shop or local auto parts store can bench test it very easily. Next, as mentioned, cleaning the points via sandpaper or a file or anything else abrasive is a no-no. 99.98% of all non-starting issues are electrically related, usually poor/bad/incorrect wiring. That being said, the first test when not starting, other than a good battery, would be to check for fuel flow at the carb. If fuel flow is sufficient, move on to the spark test. Leave distributor on and alone for now. Take your VOM, set function to VDC, and ensure the range isn?t mV or you?ll get crazy readings. Power off, take a reading of what the battery voltage is static and make a note. Take one meter probe, it doesn?t matter which one, polarity has no effect here, and probe the LH terminal connection on the ballast resistor. That is where the coil wire connects to. If it isn?t further investigation is needed before proceeding. If it?s okay, then turn the key switch ON, but don?t start tractor switch, and take the other meter probe and touch ground anywhere. You should see VDC identical to the battery voltage with points open, half that with points closed. If good, move on to top of the square can ignition coil terminal post, there?s only one, and repeat the test. If results are the same, voltage to the coil is good, the problem is likely in the distributor and/or a bad coil. NO VDC readings at the resistor post or the coil post indicate the problem is likely in the resistor, coil, ignition switch, or the wiring of any combination. The generator and VR are part of the charging system not the ignition system, however goobered-up wiring can result in any scenario. You need to use your essential manuals for help ?the I&T F-O4 Manual and the 39-53 MPC especially. Do not buy any new parts and start replacing until old ones determined to be failures. Finally, do not determine wiring by the color of the wires. The original harness is probably long gone or faded beyond recognition. New, exact-as-original wiring harnesses are available like the one shown in Steve Dabrowski's restored 1948 8N with an Auto-Lite VR below. Colors do not conduct electrons -always perform continuity to verify.
ORIGINAL FORD 8N ?AUTO-LITE? VOLTAGE REGULATOR:
NEWER/AFTERMARKET 8N VOLTAGE REGULATORS:
WIRING DIAGRAMS FOR 8N w/FRONT MOUNT:
Tim *PloughNman* Daley(MI)