Ford 8N having trouble starting -- many troubleshooting steps take -- suggestions?

[PorkChopsMmm]

I hope at all cost I will not need to wire the tractor.

The only thing ignition related I *think* I changed is taking the wires off of the OEM button when I thought the button was to blame for the starter sticking. I took the wires off of the starter button and used them to start the tractor a few times. I forgot which wires went on which pole of the start button -- so I swapped them back and forth with the same result. The engine turning over but not firing (this was a few days ago). I am going to give it a closer look tonight.

 

[94BULLITT]

I hope at all cost I will not need to wire the tractor.

The only thing ignition related I *think* I changed is taking the wires off of the OEM button when I thought the button was to blame for the starter sticking. I took the wires off of the starter button and used them to start the tractor a few times. I forgot which wires went on which pole of the start button -- so I swapped them back and forth with the same result. The engine turning over but not firing (this was a few days ago). I am going to give it a closer look tonight.

Do you have spark at the coil?

 

[PorkChopsMmm]

Ok, got back from doing some tests. I wrote up a nice long post and my phone lost it...

- Voltage at coil is *only* on when the key is on. Voltage is 11.X and drops to 10.X when trying to start
- I double checked wiring on the alternator and it all looks good. Power to the right side at all times, and power only to the top small screw and right hand lug (attached to starter) only when starting.
- Below is a picture of the wiring near the starter switch and 'relay' that is unknown to me but has a lead going to the coil. While this does look like a rats nest I made sure that nothing came undone, was corroded, or was otherwise damaged.

I have the battery charging it hopes of the battery being low causing an issue, but when I try to start the starter runs strong -- the engine has kicked over recently with what seemed like much less force.

Should I pull the coil and see if it physically sparks while trying to turn the engine over? Once the battery is charged one of my next steps will be testing to see if I have spark at the plugs.

 

[PorkChopsMmm]

Small update, I don't think the battery voltage had anything to do with it. Charged the battery and the starter ran super-fast. Like crazy fast, guess that is a good thing, but no firing.

The only odd thing I saw was that with the key on the battery measured 12.7 with a volt meter, the alternator measured 12.6 or so, and the coil measured much lower, like 12.1. It sure why it would be so much lower.

I am going to try and dig in again tomorrow night.

 

[Soundguy]

i'm reading a few things that aren't seeming correct.

1, I don't see any solenoid in your pics.

2, the 'starter' switch on an 8n is a big push button the size of your thumb on the top of the transmission. there should be a 2 pole ignition switch in the dash.

essentially, power hits the top post of the 3 terminal ballast resistor plate.. from there tot he ignition switch.. from the ignition switch back to one of the lower terminals on the ballast resistor.. from the other terminal of the ballast resistor to the coil.

since this is 12v the coil needs to be a 2.5 ohm coil.. not the oem 1 ohm coil.

if this unit uses a ammeter ( 2 post style ).. then the charge line from the alternator to one side of the ammeter.. other side of the ammeter to the hot side of the start solenoid.

line to lamp switch and the wire to the top of the ballast ressitor come off the same side of the amp meter as the alternator line. this gives you a net charge / discharge setup. a voltmeter is wired differently..

soundguy

 

[PorkChopsMmm]

Soundguy -- thanks for the help.

The picture in my post above is from the inside of the battery compartment facing the back of the "dashboard". Here are pics with the old and new solenoid.

Old:

New:

Thanks for the heads up on the flow of electricity -- that really helped me mentally picture it. I remember seeing a sticker on the bottom of the new 12V coil with "2.5 ohm" written on it.

I am going to pull plugs tonight and see if I have any spark. I am guessing that I do not. I will also try and check the coil to see if it has any juice at the coil itself.

***Just a recap for any new commers -- tractor would start but solenoid was sticking and making the starer continue to run while the engine was running. I replaced the solenoid and now it won't start.***

 

[Soundguy]

them oe solenoids only work 1 way.... IE.. bat and starter posts are not interchangeable.. as the field coil is internall hot / common to the bat terminal, and hte lil terminal is grounded by the thumb switch. thus if you hookup yer battery wire tot he starter side and hanve the solenoid on bak'erds.. the solenoid will never engage.

check that at least.

 

[PorkChopsMmm]

Thanks SoundGuy. I will check that tonight.

Would there be any damage to the coil if I removed it from the distributor, hooked up my voltmeter to it and ground, and tried starting the tractor to see what voltage was going to the coil?

 

[Soundguy]

why go to that trouble.. just unhook the top wire and measure. you will measure bat voltage with key on...

 

[94BULLITT]

Check your battery voltage 1st.