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47 Ford 8N ignition problem NO SPARK

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19K views 4 replies 5 participants last post by  ChuckH  
#1 ·
Hello all I hope someone can help me figure this problem out. I have a 47 8N tractor that is not getting spark at all. This is what I have done so far
1) replaced with complete tune up kit points set at 00.15 with gauge supplied in kit. I also purchased new 12v coil & wiring harness with ballast resister.
2) cleaned breaker plate & all screws , installed new copper tang from points to where the condensor hooks up.
3) cleaned all distributor screws -all are shiny now and getting good contact.
condensor, 12v coil, wiring harness, plug wires and plugs also converted to 12v from 6v. Ballast resister installed between toggle switch and top of coil (brown wire)
Bench tested distributor using analog ohm meter I have questions about the test results 1) when turning distributor by hand points open but I still get continuity at brass screw at condensor and coil ? isn't this wrong ? shouldn't the meter flutuate when rotating distributor open and close. I have spent hours troubleshooting this. I took the distributor completely apart nothing appeared to be wrong with it but I'm not sure I cleaned off as much rust as possible distributor shaft seems ok and only has minimal play in it.
I eventually gave up trying to figure the continuity test out. I installed the complete distributor as a unit to the 8n by just using the coil wire from the toggle switch going through the ballast resister. This is what I found when I grounded the distributor to frame I noticed a spark I then checked this out with a multi meter and voltage is present at distributor casing (question) wouldn't this be a short in the circuit or a bad distributor? I even tried to illinate all wiring and ran wire straight from good 12v battery with the same results NO SPARK out of distributor using spark tester. Please help I am at a loss with this I have searced the forums and can't find any similar problems to compare for my repair.
 
#2 ·
well, somewhat hard for me to decipher what you've done, so this may be a 'redundant' suggestion:
1. is it possible the wiring is shorting out against the distributor body where any wire passes thru any openings?
2. is the distrivbutor drive working from the engine? (rotating?)
 
#4 ·
Quote: "I also purchased new 12v coil & wiring harness with ballast resister."

If your new coil is a true 12V coil, you do not need a ballast resistor in the coil circuit. The resistor drops voltage to the coil to 6V. Which might give you a weak spark (or none at all).

As a temporary measure, hook a wire direct from the battery to the coil and see if you have spark.
 
#5 ·
"1) when turning distributor by hand points open but I still get continuity at brass screw at condensor and coil ? isn't this wrong ? shouldn't the meter flutuate when rotating distributor open and close."

Based on the year of your tractor I assume you have a front mount distributor with a square can coil. If you have continuity between the brass screw and adjustment plate with the points open, check the insulation where the copper tang connects to the brass screw. looks kind of like 30# tar paper folded over the tab.