One step forward....

Spent a long weekend at the farm “wrenching” on the vehicles. I use that expression deliberately since fixing would imply that I have the slightest idea of what I’m doing:-)

Did succeed in changing the fluids in all 5 vehicles. The guy at the recycle/haz waste site was bit surprised as I kept pulling 5 gal buckets of stuff out of the truck. 40+ Gal. Have to say the Ford 8N was by far and away the easiest to work on! Except for that 2” drain plug on the tranny. Quite a gush!. But thanks to this board I was warned..... .

But alas not everything goes as planned.... Managed to take a perfectly running tractor and make it stop running...

Ford 8N, 1949, Front mount 4 nipple 6V positive ground. New to me.

Tractor started and ran fine. Changed fluids still ran fine. Replaced oil pressure gauge, still ran (and 35 psi @ 1500 rpm). Then I replaced the headlight switch....

The tractor has been rewired in a fairly half baked way. Found a 15A household screw base fuse in series with output of ignition switch. Traced headlight wires, measured with the volt-meter that the switch was intermittent. Replaced switch, headlights worked. But now it won’t start.

Cranks fine with gusto!

Spark test weak to none.

Started poking around with voltmeter, found wire from ignition sw to coil to be flaky. It had been rubbing/melting on block and as I wiggled wire the 6volts on the coil would come and go. Replaced this wire with a new wire (18ga) from ignition switch directly to coil. Still no start. Voltage on coil with ignition switch on was -5.6V static, -5.3V cranking. (all voltages ref chassis)

Checked for “week sister” ignition switch, only 150-200mv drop across switch when cranking, 400mv with headlights on.

Then noticed that one of the nipples on the distributor cover was cracked. Spark plug wire was still connected but the phenolic housing was cracked away on one side.

About this time noticed the delightful smell of hot electronics. More a capacitor oily kind of smell, not the cooking resistor kind. Felt the coil and it was quite warm. Cooled down when I turned off the ignition. Let it cool, tried again. After leaving ignition switch on for 6-7 min coil was hot. Tar was oozing out the side, don;t know if it was there before.

Another observation was raw gas dripping out of the carb. Coming from an indentation near the drain plug. Never noticed this when it was running, on the otherhand I was in the seat driving along so I wouldn’t have noticed. Not sure this is related or not. I’ll guess not since I turned off the fuel cock as it was cranking away and cleared the gas and it never even coughed.

Opinions?

Thanks as always

Welp, yer first problem is the smell of HOT COIL TAR. yep, ya done melted yer insulative coil tars and now you can't make enuff sparkie to run yer engine.

I'm gonna guess yer screw-in house-fuse is in yer headlight wiring. I guess iff'n ya gotts no other choice, a fuse is better than none (but not much better) Replace it with a real inline automotive tube fuse = 20Amps holder. $2 (cheap) ...or... replace yer headlight switch with a built-in tube fuse clamps. That is what Ford used 60 yrs ago and modern replacements are readily available. $5 (cheap)

18ga wire to yer squarecan ignition coil is TOO SKINNY and will cause weak sparkies. Ignition primary wire in the original wiring harness is 16ga. 14ga stranded would be better.

Distributor broken nipple #2 is common indication that the front axle kingpin is worn and sloppy. Quick fix to prevent more cap breakage is to widen-out yer frontaxle 2-boltholes each side. This reduces the angle of front axle tilt and therefore reduces to upward axle movement cracking yer 4-nipple crabcap.

You write..... "Still no start. Voltage on coil with ignition switch on was -5.6V static, -5.3V cranking. (all voltages ref chassis)"..... .. You should read about -6.3 volts static. delta 0.3 volts (-5.3v) crankin' tells me yer 6 volt battery is pretty stout and yer not loosin' much to starter motor drain. ...BUT... you really need to determine what yer coil volts is when yer points are closed. Should be about -3.2volts and battery volts when points are open.

Since ya done went an melted yer squarecan ignition coil guttz, NOT MUCH else you can do until you replace yer ignition coil.

You might be "ahead of the game" iff'n you check yer distributor points gap while waiting to replace yer ignition coil. You need to remove yer 2-bolt frontmount distributor to replace yer ignition points on the kitchen table. Gap yer points 0.015". Replacement is a reversal of removal, except gently finger start yer 2-bolts and then rotate yer rotor until the OFF-SETT cam drive tang falls into place and yer distributor is automatically timed. Then finish tightening the 2-bolts. Simple, eh?

Before you install yer squarecan ignition coil, gently stretch the coils springy-thingy, so it makes good coil points contact..... ...Dell, yer self-appointed sparkie-meister

Thanks for the info sparkie-miester Couple of followups.

Fuse was absolutly in the ignition ckt. I thought it strange too but so was a lot of the electrical tape/wire nut hayseed wiring.

5.6 static was probably after the battery had been cranking for a while. I didn;t read the battery terminal directly but the headlight switch which was wired right after the ignition with no load (lights off) was also -5.6V.

How do I tell if my points were closed to measure voltage? I tried the EE approach of a 10ms sampling min/max voltmeter and got a bunch of garbage date. Strong on electronics total newbie on auto shop stuff.

I assume I replace the points if I'm going through the trouble of opening the assy up?

But thanks for the encouragment!