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8N 12 volt wiring problems

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wasilla1

01-02-2014 13:51:00

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Hello everyone, I'm new to the forums and I acquired an 8N that was converted to 12 volts by someone before me. The tractor became hard to start. It had an automotive push button starter and the wires started melting and smoking, so I decided to rewire the tractor. I looked at several online wiring diagrams, ordered a wiring harness, and rewired the tractor. Please bear in mind that automotive type electrical wiring is way over my head.
I replaced the coil, points, condenser, resistor block, voltage reducing resistor, diode, ignition switch, original type starter button, plugs and plug wires.
However, I must have something wrong. I turn on the ignition key and push the starter button and nothing happens and yes, it"s in neutral.
The way I have it wired is nowhere near the way the person before me had it wired. They only had two wires on the alternator, the top #1 wire was just dangling loose and starter button was wired directly to the starter.
Also, do I even need the voltage reducing resistor?
Attached is a photo of the way I have it currently wired. What do I have wrong? Thanks in advance for any advice.

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arnold z

01-03-2014 17:55:46

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 13:51:00

The small post shouldn't turn. It should be locked with a nut, then your terminal goes on, then another nut.

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wasilla1

01-03-2014 18:06:36

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Re: 8N 12 volt wiring problems in reply to arnold z, 01-03-2014 17:55:46

Thanks. I didn't think it was supposed to turn, but it does have a knurled knob so I wasn't sure.

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JCinKY

01-04-2014 08:42:56

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-03-2014 18:06:36

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You've just about got her. Sounds like a new solenoid (or repair the old if possible) and you'll be up and running.

As stated the small stud should have 2 nuts, one "jam" nut for the stud and one "lock" nut for the terminal. Try finding a matching nut to tighten up the terminal and another for the wire. It might just be too loose to make the needed connection.

If you do get a new solenoid make sure it is for a tractor. And one that is GROUND activated. A car solenoid usually has 4 posts instead of three. Some will work, some won't. Heck, get one here and support YT.

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wasilla

01-13-2014 15:39:37

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Re: 8N 12 volt wiring problems in reply to JCinKY, 01-04-2014 08:42:56

Thanks again, I had to go back to work....I work in the oil & gas business out in West Texas. Won't get to work on the tractor again until the end of the month when I go back home. I ordered a tractor solenoid so hopefully at the end of the month I'll have this thing fixed.

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teddy52food

01-02-2014 17:49:04

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 13:51:00

Leave the charging circuit as is. It won't change the starting circuit. On that solenoid, check if there is voltage on the small stud. If there is, the starter button has to complete the circuit to ground. If it is dead, you may have to apply juice through the start button to activate the solenoid. Or it may be reversed on the 2 big cables.

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wasilla1

01-02-2014 18:11:18

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Re: 8N 12 volt wiring problems in reply to teddy52food, 01-02-2014 17:49:04

I put a test light on the small post on solenoid that points toward the engine block and it didn't light up.
Remember I'm in over my head on electrical wiring so please explain "apply juice to the starter button".
I have a new solenoid on order. Hopefully it comes in tomorrow.

Thanks

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JCinKY

01-02-2014 19:44:01

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 18:11:18

wasilla1 said: (quoted from post at 19:11:18 01/02/14) I put a test light on the small post on solenoid that points toward the engine block and it didn't light up.

Remember I'm in over my head on electrical wiring so please explain "apply juice to the starter button".

I have a new solenoid on order. Hopefully it comes in tomorrow.

Thanks

The small stud facing the engine should be hooked to your button, which will eventually be a ground when you push it down.
Since the solenoid is wired batt hot, grounding it closes the contacts and completes the start circuit through the solenoid, (its an electro-mechanical thing).
Depending on your light you may not get it to light. Hook the clip on batt hot then touch the probe on the small stud. Now push the starter button down, it should be green for ground if you have the right light. Let go of the button and you have nothing since the circuit is no longer complete.

The opposite test would be to reverse the clip and probe. Should be red with button down, and, again, nothing with button up.

Take a jumper wire from batt hot and BRIEFLY touch the stud on the starter. As in the one on the starter barrel most toward the oil filter. It should try to roll over. BE CAREFUL OF ANY SPARKS. If it does try to rollover, solenoid is bad or wrong. Or starter button is not making ground contact.
This post was edited by JCinKY at 19:49:45 01/02/14.

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wasilla1

01-02-2014 19:55:57

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Re: 8N 12 volt wiring problems in reply to JCinKY, 01-02-2014 19:44:01

Thanks for explaining. I will try this tomorrow. Please check this thread tomorrow as I will post what happens.

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JCinKY

01-02-2014 20:02:11

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 19:55:57

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No problem. Bout to hit the hay.

You will get lots more advice. The old folks tend to shut down early. :D

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wasilla1

01-03-2014 17:46:25

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Re: 8N 12 volt wiring problems in reply to JCinKY, 01-02-2014 20:02:11

Ok. The test light wouldn't light up. I removed and reinstalled the starter button, just in case I screwed something up the first time.....no way to screw that up...only fits one way.
I put a jumper wire from positive side of battery to front post on starter and motor turned over. So I'm assuming my solenoid is bad. Also I noticed the small post on solenoid pointing toward motor rotates fairly freely. Is it supposed to do that?
My new solenoid didn't arrive today...hopefully tomorrow.
Thanks for the help.

Bill

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JCinKY

01-02-2014 17:47:08

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 13:51:00

1 wire vs 3 wire doesn't matter. It has nothing to do with the start/run circuit. Personally I'd leave it 3 wire since it will excite at less rpm (500 as apposed to 1800 with 1wire.)

I'd work on getting it to start and run first, then tackle each sub-system individually.

My point is right now you can take the alternator out and you'd be in the same boat. Even the best alt in the world is just scrap metal without a starting/running engine to spin it.

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JCinKY

01-02-2014 16:17:32

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 13:51:00

Your wiring diagram looks right to me. And you generally have all the parts and pieces necessary.

The additional resistor can work, but again that can vary based on the coil. Lets forget about that for now until it turns over.

Lets also assume your starter button and switch are good too since they were replaced. The most common culprit in my eye is the solenoid. It looks correct in your pic, but without a closer look it hard to tell. Do you get a clicking sound when you hit the button? Is the battery good and charged?

You can jump around the solenoid to check it. MAKE ABSOLUTELY SURE ITS IN NEUTRAL WITH THE KEY OFF. Just bump it and see if it starts to turn over.

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wasilla1

01-02-2014 17:30:22

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Re: 8N 12 volt wiring problems in reply to JCinKY, 01-02-2014 16:17:32

Battery is fully charged. I put it on charger and made sure. Ignition switch and starter button are brand new. I've wired this for a 3 wire alternator, however, I think I need to wire it as a one wire alternator. When I tackled this project, there were loose wires just dangling on some things and it looks like they used old wire to splice together to get enough length to use. A wire that started out red was spliced to white and then ended up at the other end as a black wire. That's why I decided to redo everything and do it right. My son helped me remove the wiring and he disconnected some things without me being able to see how the previous owner had it wired. I think I'm going to reconnect everything as a one wire alternator and see if that works.

Thanks,
Bill

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arnold z

01-02-2014 14:02:50

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 13:51:00

The only thing I see is if you have the wrong solenoid, it doesn't work. To use the original start button, you need a solenoid that takes ground to activate. If it has one small post it should be where the 'I' one is on one that has I and S on the two small posts. If you have a single small post, but it's where the S is on a double post, it takes voltage to activate. The wiring looks right if it matches you pic.

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wasilla1

01-02-2014 14:38:54

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Re: 8N 12 volt wiring problems in reply to arnold z, 01-02-2014 14:02:50

Attached is a photo of the solenoid that's on it now.
Sorry, but I didn't really follow what you wrote.

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Bruce (VA)

01-02-2014 13:58:07

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 13:51:00

" Also, do I even need the voltage reducing resistor?"

Maybe.

Does the tractor have a front or side distributor?

What does the resistor look like?

Got a model/make of the alternator?

75 Tips

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wasilla1

01-02-2014 14:48:27

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Re: 8N 12 volt wiring problems in reply to Bruce (VA), 01-02-2014 13:58:07

So, should I wire this as a single wire alternator??

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wasilla1

01-02-2014 14:34:41

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Re: 8N 12 volt wiring problems in reply to Bruce (VA), 01-02-2014 13:58:07

It is a front mount distributor.
It is a Delco-Remy alternator. I couldn't find any numbers on it, but post at rear says BAT.

I'm not positive of year of tractor...either a 1947 or 1948. Serial # is hard to read, real faint stamping, but it looks like 8NF1129????

The pic is what the new resistor I put on looks like. I will also try to post a pic of what I assume was a resistor that I took off. It would get cherry red hot and tractor would die. I would wait about 10 minutes for resistor to cool off and tractor would run for a while until it got cherry red hot again and die.

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Bruce (VA)

01-02-2014 14:50:02

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 14:34:41

See tip # 30 at the link; get rid of that resistor. Get the OEM ballast resistor (as in the picture) and a 12 volt coil.

Re the rest of the wiring, Google "wiring diagrams JMOR" and pick the one that fits your alternator.

Post back w/ results or more questions.

75 Tips

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wasilla1

01-02-2014 14:58:36

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Re: 8N 12 volt wiring problems in reply to Bruce (VA), 01-02-2014 14:50:02

I put that one on. New block and resistor. It's in the top right center of my drawing on the original post. Internet research led me to believe I needed an additional one which is the voltage reducing resistor on the top left of my drawing.

Thanks,
Bill

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carlntexas

01-02-2014 16:17:48

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Re: 8N 12 volt wiring problems in reply to wasilla1, 01-02-2014 14:58:36

I'm far from an expert on this,but I did rewire my 8N. It looks to be wired right from your drawing. Try shorting the wire to starter button to a good ground if it starts your button is bad. If this doesn't work you could have the wrong solenoid.

Looks like Jcinky answered better than me while I was typing.
This post was edited by carlntexas at 16:24:16 01/02/14.

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wasilla1

01-02-2014 18:04:45

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Re: 8N 12 volt wiring problems in reply to carlntexas, 01-02-2014 16:17:48

Thanks. I'll try that tomorrow.

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arnold z

01-02-2014 14:19:10

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Re: 8N 12 volt wiring problems in reply to Bruce (VA), 01-02-2014 13:58:07

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A lot of assuming on my part :) Better question is it for sure a 8N? I've bought a few Ns that had some wierd combos of resistors and coils that worked, and some that should have that didn't. The coils are pretty inconsistent nowdays.

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