8N Electrical Issue

[aschwerin]

1948 8N (front coil) converted to 12V before I had. So a couple years back I got this tractor running, but have had starting issues since the beginning. I have followed wiring advice, and have replaced solenoid twice, battery twice, starter rebuilt and also replaced with new starter, and new alternator. Most of those money-grubbing replacements did not help anything.

I generally have had to start the tractor with two 12V batteries (jumping). Starts well with a rolling start. Now I can not get it to turn over even jumping with a running car. At best I get a solenoid chatter. I have four terminal solenoid (not ground-activated), and the S is only showing 2-4 volts when I turn ignition to start. No spark if I jump from positive battery post to starter post. Just now I figured out if I take red cable off post and then jump from battery post to starter I get very strong "welding" sparks, but starter makes no effort to turn. Pretty sure same thing happened with the rebuilt starter. Starter to frame contact has been polished and bolts are quite tight. Hard to believe that poor grounding could be an issue. When I took the rebuilt starter out it would give a superfast whizz when jumped. I have tried all three solenoids I have sitting around. (Solenoid is frame mounted, not starter mounted.)

I think I have been "compensating" for some issue now, and it would be really useful to have a tractor that starts. Help

 

[LD1]

Not sure what you are talking about there being no sparks and then very strong welding sparks. Are you talking about spark at the plugs?

Now your jumping proceedure. Are you still trying to jump by using the tractor battery, and still using the start button on the tractor? or are you jumping straight to the starter?

Only getting 2-4 volts at the S terminal on the solenoid causing it to just chatter tells me you either have a bad connection there, or not getting enough juice through the start button.

Maybe not a good thing to suggest, but try running a hot wire straight to the S terminal and see if it turns over. But be aware, you are bypassing the safety of having to have the tractor in neutral. So MAKE SURE the tractor is out of gear. Cause if in gear, the tractor can/will lunge forward and possibly start while in gear, causing a run away.

 

[aschwerin]

With all wiring in proper place, if I jump from Hot to Starter there is no effect. If I remove positive battery cable, and jump from bare positive battery post to Starter there is a lot of electricity (strong sparks) but starter does not turn.

No start button, but ignition key, so there is no safety (that issue is another thread). I have tried jumping straight to S terminal and there is no spark, no starter turning. When key is turned one notch, the I terminal does show 13 volts and the S terminal shows near 0 volts.

 

[LD1]

If you are jumpstarting and applying 12V direct to the starter and all that is happening is lots of sparks, either

1. The engine is locked up
2. The starter is bad.

Try removing the starter from the tractor and see what is going on

PS: assuming when it was converted to 12v, it is now negative ground? and we are refering to the "hot" jumping to the starter as positive correct?

 

[Soundguy]

This tractor would benefit from a back to basics wire harness, key switch and solenoid and is start button.

1 st, verify connections especially chassis ground, as kd said, starter could be hung un rung gear ir engine not turning, it starter bad

12v, thus needs a ballast resistor and2.5 ohm coil, ir original coil, resistor, plus a conversion resistor

 

[Scrambler82]

Wondering, is the starter a 6 volt or a 12 volt unit ?

The six volt start may require less voltage but more amperage to operate.

As stated too wiring, grounds especially, need to be in good condition.

Have you done anything to the wiring ?

Did anyone rewire the tractor when they went 12 volts on the alternator ?

 

[aschwerin]

1. The engine runs fine once it starts. I wouldn't consider that locked up.
2. I replaced the original starter with an aftermarket starter a few months ago. No symptoms changed. Starters work fine when removed from tractor.

PS. I have the negative battery connected to ground. Hot is +

 

[aschwerin]

Soundguy,

All connections are clean and tight, so I think. I don't know about hung on rung gear, this is an ongoing issue, not one instance. I replaced starter earlier this year out of frustration. Nothing changed except $110 less in my wallet and an extra starter in the garage.

I did research resistor and I believe I have that correct. Engine runs fine when it turns over, just having trouble getting starters to turn. I am quite sure if I went and bought the biggest baddest battery at the store it would do the job for some time. But that doesn't seem how this tractor should work.

 

[aschwerin]

Scrambler, I believe it was original starter, so 6V. I replaced with the aftermarket $110 one at New Holland. No change.

It looked to me like somebody rewired the tractor, probably when changed to 12V. I rewired some connections when I replaced solenoid. Even had the ground switch hooked up for a little while (completely disconnected now). New wire to coil. I replaced the alternator a couple weeks ago, and switched from the 1-wire setup to 3-wire setup. Replaced ampmeter with voltmeter yesterday.

For about a year I parked it facing downhill and started it by rolling. Sometimes that's hard to do depending on the implement behind it. If that didn't work, or if I stalled it, I'd drive the truck over and jump it. I'm real tired of that stuff.

 

[Xfaxman]

With all wiring in proper place, if I jump from Hot [What and where is "Hot"?] to Starter there is no effect. If I remove positive battery cable, and jump from bare positive battery post to Starter there is a lot of electricity (strong sparks) but starter does not turn.
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?? This is not logical. ?? Unless there is no connection between the battery + post and the cable clamp that is on it. When you jump from Hot to Starter are you using a jumper cable clamped on bare positive battery post and pushed as hard as possible against the starter terminal? It won't spark once good contact is made.

It would help if you could post a picture of the starter and show the terminal you are using.

Watch this video, it will help you troubleshoot the circuit: https://www.youtube.com/watch?v=XhRPLgH6uZg