1946 ford 2N resistor question/wont start

Snarfblat

New User
A friend has a 46 2N that he was using to mow. He
stopped to gas up and climbed right back on but
the tractor would not start. He tried a set of
points and condenser, and a coil. still no go. so
went over to eyeball it with him, and we wound up
at the ceramic resistor. it had 11.97 volts to it,
1.6 on the other post with the wire going to the
coil...and with the key on it almost immediately
was too hot to touch. He had a new in the box
resistor so he wanted to try it, as the very low
voltage heading out and the getting so hot didnt
seem right. Did the same thing, only difference
was the readings, 11.95V and 1.9V. Can anyone shed
some light on whats maybe goin on with the
resistor that would cause the very low readings
out and what might make it get so hot? im of
course guessing when we get things with that
straightened out, itll solve or point to the not
starting issue. thank you so much for any help in
advance!!
 
(quoted from post at 10:54:31 08/15/14) A friend has a 46 2N that he was using to mow. He
stopped to gas up and climbed right back on but
the tractor would not start. He tried a set of
points and condenser, and a coil. still no go. so
went over to eyeball it with him, and we wound up
at the ceramic resistor. it had 11.97 volts to it,
1.6 on the other post with the wire going to the
coil...and with the key on it almost immediately
was too hot to touch. He had a new in the box
resistor so he wanted to try it, as the very low
voltage heading out and the getting so hot didnt
seem right. Did the same thing, only difference
was the readings, 11.95V and 1.9V. Can anyone shed
some light on whats maybe goin on with the
resistor that would cause the very low readings
out and what might make it get so hot? im of
course guessing when we get things with that
straightened out, itll solve or point to the not
starting issue. thank you so much for any help in
advance!!
ood starting point would be to install the correct resistor instead of just any ceramic block.
 
Well..if I were a betting man...I'd say he's got it converted to 12 volts... Does he have the original ballast resistor?
 
Snarfblat........gotta love that handle (giggle).......1st off, the infamous ballast resistor gitts HOT, infact it gitts RED-HOT. This is normal.

Howsomevers.......1.6-1.9-volts at the other side of the resistor is NOT normal. Should be about 3-volts. Low volts means weak sparkies and NO START.

Now pay attention here. Yer otherside of the ballast resistor can have 2-types of volts......same volts coming out as going in.....(ie 12-volts, and COLD ballast resistor).....OR.....some lower value of volts caused by CLOSED points. Ittza LAW, Kerchoff's Law.

I'm gonna make a WAG that yer points closed. They're known fer slippin' on the 8-32 adjust screw. The points should be gapped to 0.015in. Ittza 15-min job to remove the 2-bolts and adjust the points on the kitchen table. Just un-snapple the capple and letter dangle and walk. While you maybe lucky, but new points need to be "polished" after you install them. Just clamp a clean matchbook cover between the points and pull. Simple, eh?

Finger start the 2-bolts and install the rotor and twist. The dizzy is OFF-SET and needs the rotor to match the OFF-SET drive tang. When aligned up, the dizzy will drop-into the OFF-SET drive slot. Now tighten the 2-bolts and re-snapple the capple. Simple, eh? .......Dell, yer self-appointed sparkie-meister
 
The problem you are having is the very reason for tip # 30 at the link.

As JMOR suggested, there is a lot more to it than just installing "a ceramic resistor".

We can all expand on what Dell is telling you if you want an in-depth explanation of why the tractor won't start......but, I'll guess you'd rather skip Electronics 101 and just get it fixed.

So, go buy a 12 volt coil & the OEM ballast resistor (like the one in the picture). Install them correctly & the tractor will run just fine.
ff5614e4-6e4e-4d93-bacf-b351f246f004_zpsa49e8a9b.jpg

75 Tips
 
to rule out bad wireing. hot wire from bat thru resistor to top of coil using jumper wires. see what you get.
 
(quoted from post at 07:43:51 08/16/14) This guy on Ebay shows a wiring digram of the Conversion. He show using the infamous ballast resistor and a ceramic block resistor plus a 12 volt coil. If you have the 12 volt coil, why would you still need the ceramic block resistor? I thought that was used only when using a 6 volt coil on a conversion
Ford 8N 2N 9N Tractor Generator to Alternator Conversion Kit
ou don't. Just remember, "a great many things are made to be sold, but not to be bought".
 
Help! Limited mechanical/tractor background owner has 2N won"t start. Need advice before traveling 225 miles to continue repair. No spark at downstream end of wires. Wires ring fine. Changed out 6v cracked and oozing (dielectric?)ignition coil. Have 6v in/out now. Replaced pts/condenser,(original pts were damaged)but think vendor err"d with part#. Can"t get pts to close and strips seem way to long. Going to try with new set soon. Need direction if new pts don"t resolve. Want to avoid new dist. Thx!
 
" So you are saying it is wrong to use that resister in that case? "

Yes.

It's all very simple if you apply Ohm's Law.

If the coil is 2.5 ohms or or more.....and the OEM ballast resistor is 1.7 ohms hot, you have 4.2 ohms resistance in the ignition circuit.

14.5 volts divided by 4.2 ohms equals 3.4 amps when the tractor is running. That's fine.

But, at start up, the ballast resistor is .03 ohms. That's 2.8 ohms total, meaning the tractor is starting at 5.1 amps.

That's fine too.

What happens if you add more resistance w/ a fixed ceramic resistor?

You get a weak spark.
75 Tips
 
The first thing you need to check is bushing wear. If the shaft has any sideways movement AT ALL, the bushings must be replaced.

Assuming that the bushings & advance weights are ok (*see below), & that you have correct voltage to the coil (battery voltage with the points open and about half that with the points closed), the most common electrical failure (no spark, weak spark) points on the front mount are:

1. The insulator under the brass concave head screw & where the copper strip attaches. (it’s fiber & will wear out; poke & prod w/ your meter leads to make sure it still works) If you need to replace the insulator, use a .250 x 3/8 nylon square nylon anchor nut available at most big box home stores

2. The pigtail at the bottom of the coil not making contact w/ the concave head brass screw inside the distributor. (With the coil on, the pigtail must firmly contact the brass screw. No contact = no spark

3. The copper strip is broken or grounded to the plate. (look very carefully for cracks & breaks).

4. The condenser wire grounding to the plate or side of the distributor.

5. The tab on the bottom of the coil not making contact w/ the brass button on the cap. (With the cap on, the tab must firmly contact the brass button. No contact = no spark.)

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground. (the open part of the clip goes between 7 & 9 o’clock on the plate. That puts the straight part of the clip opposite of the timing screw at 3 o’clock)

7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket.(the coil must not move at all; if it does, replace the gasket or bail. Or stick some cardboard under the bail).

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket. (the cap AND coil have gaskets)

9. Dirty/corroded/burned/incorrectly gapped or misaligned points. I use only Wells, Blue Streak or Echlin brand points (* *see below).

10. Burned rotor, cracked/carbon tracked cap.

After you find the problem & re-check the point gap, do a continuity check before you put the distributor back on the tractor. Before you start, make sure your meter/light works.

With the distributor still off the tractor, follow these steps:

1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.

2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.

3. Put the coil on the distributor, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

At this point, I just put the distributor, coil & cap all back on the tractor as a unit. The reason I do this is because it is real easy to get the cap or coil misaligned trying to put it back together, one piece at a time. The result is something gets broken or you get a ‘no spark’ problem.

It's possible to put it back on wrong & break it. Look at the slot on the end of the cam shaft. Whatever angle it happens to be, turn the distributor tang to match it. Make sure you can tell the wide side from the narrow side on both the cam & distributor! (close counts). Place the distributor on the front of the engine, gently push it in place & slowly turn the distributor body until you feel the tang slip into the slot. Rotate the distributor body until the bolt holes line up. Hand tighten the two bolts until the distributor body is flush with the timing gear cover.


* Unscrew the plate hold down screw & remove the C clip to get the plate out. Remove the shaft & weights. The weights should freely move.


* *NAPA part numbers:

• Points: FD-6769X
• Condenser: FD-71
• Rotor: FD-104
• Cap: FD-126
75 Tips
 

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