8N Starting Problems

[tderrick]

I've been conversing with my tractor guru, @Soundguy about what I thought would be a simple problem with the starter on my 8N.

It has progressed to bonafied confusion at this point, however. I thought I would bring everyone in on the game in case someone
else runs across this strangeness.

From the top....

Tractor fails to start after trying to restart it hot in the field after I shut it down and cleaned off the bush hog.

Go to fire it up and I get the classic buzzing sound from the starter solenoid. "No problem" I think, It's just hot and I'll try again
after it cools off. The next morning, no go... same sounds. I check all the wiring and decide to change out the solenoid after
checking that the battery seemed fine.

Get a solenoid, install it the same way the other came off and now - nothing, not a sound.
I tried taking the solenoid control wire straight to ground, bypassing the push button switch and still nothing.

I'm sure I got the wiring back on right,,.
The small control ground post faces the block.
The battery hot goes the the post facing the battery and the other post pointing to the
front of the tractor is connected to a 90 degree bar to the bolt on the starter.

How hard can this be? ... sheesh..

Advice is what I need now... The fields are close to seeding weeds and I need to get a lot cut.

Help out a man, will ya ?

AJ

 

[Bladehauler]

most solenoids are triggered by a hot wire from the switch , not by grounding it . but I have no experience with the ford 8ns. still i believe I would try a hot wire to the solenoid trigger

one other thought , I,ve had the battery cables go bad before, would carry enough current to run the machine but not start it, I took jumper cables and mirrored the battery cables , in other words , - from batt to engine ground , + from batt to starter , reverse that if its a + ground system.

hope this helps, good luck

 

[tderrick]

Thanks for the input, but the control post leads to the starter "button" mounted on the tranny plate by the shifter. I assume
the only thing this switch can do is go to ground.

most solenoids are triggered by a hot wire from the switch , not by grounding it . but I have no experience with the ford 8ns. still i believe I would try a hot wire to the solenoid trigger

 

[tderrick]

Another thing I thought of is that the polarity of the solenoid is opposite of the one removed. In other words,
the small control post faces out, away from the block.

Has anyone ever had one that mounts in reverse fashion?

 

[Bladehauler]

yup , just looked it up , its a + ground system 6 volt . right ? I would try jumper cables from the battery to the engine ground and the starter terminal. that eliminates everything in the circuit but the battery and starter. if it cranks , you can work backward from there

 

[Bladehauler]

Another thing I thought of is that the polarity of the solenoid is opposite of the one removed. In other words,
the small control post faces out, away from the block.

Has anyone ever had one that mounts in reverse fashion?[/QUOTEI bet you just found your problem , if the solenoid triggers by grounding , it has to get its power for the other side of the coil from 1 of the batt terminals, my guess is youve got the terminal that should be on the batt side hooked up to the starter side by mistake

 

[tderrick]

Oh, I like that idea... Is the engine ground the same as the destination of the battery ground? It bolts to the chassis,
right behind the instrument cluster.

...and would I need to pull the solenoid off for the test?

yup , just looked it up , its a + ground system 6 volt . right ? I would try jumper cables from the battery to the engine ground and the starter terminal. that eliminates everything in the circuit but the battery and starter. if it cranks , you can work backward from there

 

[tderrick]

Correct. that is the factory setup. Mine was converted to 12V, negative ground, however....

hey.... I picked up a 6V OEM type solenoid. I wonder if it was 12V I pulled off and somehow there IS a polarity issue.... hmmmmm
I was going to reverse it and try, but the bugs and heat were coming in fast, so I called it a morning and will try
when it's cooler... (after the starter test you mentioned)

yup , just looked it up , its a + ground system 6 volt . right ? I would try jumper cables from the battery to the engine ground and the starter terminal. that eliminates everything in the circuit but the battery and starter. if it cranks , you can work backward from there

 

[Bladehauler]

Oh, I like that idea... Is the engine ground the same as the destination of the battery ground? It bolts to the chassis,
right behind the instrument cluster.

...and would I need to pull the solenoid off for the test?

nope , just hook the cables up - battery to preferably the starter ground ( like the mounting bolt ) and the + from the batt to the starter terminal. if it cranks then try the + on the starter side of the solenoid . that will confirm that the cable between solenoid and starter is good, I dont think a 6 volt solenoid will last long at 12 volts. I would imagine the coil inside will overheat and kill the solenoid

 

[Soundguy]

ford 8n tractor solenoids do indeed use a small ground wire to the 3rd terminal. correct oe units are installed with the lil terminal facing toward block. i have seen some repops wired backwards wher ehte lil terminal faces out.

also could be assembled wrong and need power ont he small terminal.

east to chack all 3 situations.

however.

that 1st one buzzing. probably not a bad solenoid anyway... probbaly a bad connection.. bat cable, terminal end.. etc.
corded wire inside the sheath.. etc. bad bat.. dragging starter due to bushings.. etc. seizing engine..e tc.

i'd double check all those.. easy ones first.

jumping around solenoid is an easy check