'52 8N Electrical Issue

[Jim.ME]

The stud with the battery cable hooked to it should have battery voltage. The stud with the strap going to the starter motor will not have voltage until the solenoid is energized.

If the original starter button is used it grounds the small terminal to energize the solenoid. Some solenoids can only be hooked up one way to work.

Can you test continuity? If so, test for continuity between the stud the starter strap is hooked to and the small stud that has the wire from the starter button hooked to it. If there is continuity between those two the battery cable and the starter strap need to swap studs so that the small terminal gets powered via the battery cable; the starter button will then provide a ground for the solenoid to pull in and energize the starter.

 

[used red MN]

If the original starter button is used it grounds the small terminal to energize the solenoid. Some solenoids can only be hooked up one way to work.

Can you test continuity? If so, test for continuity between the stud the starter strap is hooked to and the small stud that has the wire from the starter button hooked to it. If there is continuity between those two the battery cable and the starter strap need to swap studs so that the small terminal gets powered via the battery cable; the starter button will then provide a ground for the solenoid to pull in and energize the starter.

I agree, this expounds on my reply 16. Jim L’s reply 20 basically makes the same check with a volt meter.

 

[R Geiger]

I’ve tried to find where to enter the forum with my question, but I don’t see a clear way(?). Help!!

Front mount distributer, new 6 volt coil, new points and condenser. Engine operated and after trying to start again — now no spark again.

New carburetor acting now the same as the old carburetor - floats inside the carburetor will not stop the fuel from overfilling the carburetor (?).

Ken Sikora 1

When you are on this forum page, at the top right hand corner there is a link to post a new comment. easy peasy!

 

[bernieblue]

Not sure what you mean by "non grounded side of the battery". Would this be the positive battery post with the grounding cable removed from the battery?

 

[soaked]

"Non grounded side" only means the side not grounded. Does not suggest pulling off the ground cable.
Your 51 12 volt 8n IS negative ground--- right?

Here is a N solenoid.
Blue arrows point to the electromagnetic coil wire ends. One to the small terminal, and the other to the rear facing big lug. They should have continuity. ( maybe .7 ish ohms) The small terminal will show battery volts. (dont need to push the starter button, it's hot as long as the battery is connected up to the tractor)

Screwdriver showes the defection ability of the copper contact disk. (pic showes an "extra" contact/plunger)

When you got battery volts across the solenoid (between large posts) its because the starter post (field terminal) connects to ground through the field coils, and armature windings. It's a good reading.

 

[Jim.ME]

Not sure what you mean by "non grounded side of the battery". Would this be the positive battery post with the grounding cable removed from the battery?

Clarify for us, what ground your tractor is using. It was originally 6-volt positive ground. You have posted it was converted to 12 volts, but not the ground. That is why Jim L said the non-grounded side of the battery. Until you say outright which side is ground we are only assuming which it is.

As for your solenoid test in post 14, it is not correct. See the instructions I gave you in post 21. The single small terminal needs to show power all the time for the grounding starter button to work, that requires continuity between one large terminal and the small terminal. And the cable from the battery needs to be on that large terminal.

Edit to correct spelling

 

[Eman85]

OK, answer the question of which battery terminal connects to the frame of the tractor(ground). Follow what Jim and soaked have said. I am thinking you put the solenoid on backwards but that's just a guess. Do their tests and tell us what you get.

 

[bernieblue]

It's negative grounded.

 

[bernieblue]

OK Jim. You have figured out by now that electrons are not my strong suit and I apparently haven't given you a clear complete picture of what I have. The tractor was converted some time in the past from a 6v system to a 12v system. Presumably the original 6v system was grounded positively. It is now negitavely grounded. In the photo the solinoid is mounted with the small post to the rear which is the way it was mounted before I had the problem I described originally. There is a wire connecting the small post to the starter button. That's the only wire attached to the starter button which seems strange to me. I guess the small post gets grounded when the starter button is pushed The cable you see connected to the solinoid is connected to the positive battery post.
I conducted the test you asked for above. When I pushed the starter button I got a very strong click, a quick read of volts, and then no reading at all.

 

[Eman85]

Try and answer all of Jim's questions.
Does the small terminal on the solenoid show voltage all of the time?
When you pushed the starter button to make the click and a reading of volts where did you have the meter connected?

 

[Jim L WA]

bernieblue, because of the click when you pushed the starter button, it sounds like it's wired correctly. Did you ever clean the battery posts and cable clamps and both ends of the battery cables with a wire brush like I suggested back on Oct. 12? What happens is, a volt meter takes very little current to read volts. But the starter motor uses a lot of current. If the battery connections or loose or corroded they can't pass the current needed to turn the starter. Way back, when the battery cable shorted out on the manifold it may have arced at those battery connections and corroded or contaminated them.
Auto supply stores should have a nifty little tool to clean the battery posts and clamps. Shouldn't cost very much.

 

[Jim.ME]

OK Jim. You have figured out by now that electrons are not my strong suit and I apparently haven't given you a clear complete picture of what I have. The tractor was converted some time in the past from a 6v system to a 12v system. Presumably the original 6v system was grounded positively. It is now negitavely grounded. In the photo the solinoid is mounted with the small post to the rear which is the way it was mounted before I had the problem I described originally. There is a wire connecting the small post to the starter button. That's the only wire attached to the starter button which seems strange to me. I guess the small post gets grounded when the starter button is pushed The cable you see connected to the solinoid is connected to the positive battery post.
I conducted the test you asked for above. When I pushed the starter button I got a very strong click, a quick read of volts, and then no reading at all.

The small post on the solenoid is supposed to be connected internally to one of the large posts of the solenoid. That connection provides power to the coil inside the solenoid all the time. When you push the starter button it is supposed to provide the ground for the coil, which energizes it to pull the heavy contacts together inside the solenoid and operate the starter. The mounting base of the solenoid for your tractor does not provide a ground. This holds true whether the system is 6 or 12 volts and positive or negative ground.

I agree with what Jim L WA posted above, the click sounds like it may be wired correctly. Dirty cable connections can show power but drop out when a load is applied. Check/clean both ends of both cables and the attachment points.

 

[bernieblue]

I had to go back and review all the posts. I had a hard time wrapping my head around how a solinoid really works and I suspect much of your confusion stemed from you not knowing we are dealing with a negative ground system. So hear goes with answers to ALL the questions.

1. Post #2 - Yes Jim L, I turned the battery around so that the positive post was on the same side of the tractor as the solinoid and replaced the positive cable with a new 10.5" cable. I measured the battery voltage and got 12.75v. The battery posts and cable clamps are clean.
2. Post #4 - Eman, I dont know if the starter button is factory but it's mounted at the lower left of the instrument panel. You subsequently verified corrct replacement parts in post #7.
3. Post #7 -Eman, Voltage at the battery cable where it connects to the solinoid is 13v. (at this point I'm following your instructions about grounding the small post on the solinoid. No click. I then measured the voltage accross the solinoid, big lug to big lug, and expected to see zero voltage. Instead I get 13 volts which tells me the solinoid switch is stuck and why isn't the engine cranking over? Boy, am I confused. I see now why you guys get paid the big bucks). I checked the switch with an ohm meter as instructed and got an open loop and when I pushed the starter button I measurts 13v.
4. Post #16 - used red MN - Sir, you just described my confusion as stated above. Do I have the solinoid installed backward? As I said in a later post I installed the new solinoid the way it was when things were working.
5. Post #20 - Jim L - I performed your chesk and got 0 volts.
6. Post #21 - Jim.ME - By "starter strap" I'm assuming your talking about the side of the solinoid connected to the starter motor. Dou=ing your test I get 13v. Again, sounds like the solinoid needs to be turned around.

Gentlemen, it seems as though the best thing I can do is turn the solinoid around and start over again. Do you agree? Also, I suspected that when the battery cable shorted I may have broken the connection of the small wire coming from the alternator. What does this wire do? Would it have had any effect?

 

[Jim.ME]

Yes, I was referring to the copper strap between the solenoid and the std on the starter motor.

Did you get 13 volts on the solenoid post with the battery cable  and the small stud on the solenoid? If you did the solenoid is wired correctly. If not try moving the battery cable to the opposite large post and check the small terminal again. Turn the solenoid around if needed.

 

[soaked]

Hi bernieblue,
your solenoid it mounted the direction Ford intended.
Your meter should read battery volts if meter probes are placed on each big lug on the solenoid.
Why?? Answer,, starter post leads to ground

I posted this at the bottom of post # 25:

"When you got battery volts across the solenoid (between large posts) its because the starter post (field terminal) connects to ground through the field coils, and armature windings. It's a good reading."

Your solenoid isn't stuck, a likely explanation is too much resistance.

It's possible your battery and/or negative battery cable are responsible for the starter not turning, due to the short to ground event.

Suggest do a Voltage Drop Test, like this. Black probe to bat neg post, red probe to bolt grounding the negative cable.
Push starter button down. My starter is turning and .529 volts are dropping. 0.2 or less would be a good reading, this 8n has an old ground cable.

How much is your negative cable dropping? If not very much,( say less than 2 volts maybe) it points to a damaged battery not having enough amps.
Its very easy do.

 

[used red MN]

You have figured out by now that electrons are not my strong suit

I then measured the voltage accross the solinoid, big lug to big lug, and expected to see zero voltage. Instead I get 13 volts which tells me the solinoid switch is stuck and why isn't the engine cranking over? Boy, am I confused.

Just to maybe help you out a bit. You have the system set up negative ground so everything I am going to reference will be based on that and I am going to call battery voltage 12 volts due to it being a common term. The large terminal on the solenoid connecting to the battery cable brings 12 volts to the solenoid. Then on the opposite side of the solenoid is the strap connected to the terminal that goes into the starter that powers the starter when the solenoid closes. If you look at the photo of the solenoid soaked shows opened up in reply 25 you see the ends of those terminals inside the solenoid. One of the deals with the round brass washer on it shown in front of it goes in there and the magnetic coil pulls the brass washer against the two terminals to connect the 12 volts to the starter motor to turn it. However, in the normal state when you are not trying to start the tractor the brass washer is backed away from the terminals. The starter due to the way it is made to do its job has continuity through its circuits to ground via the starter case being bolted to the engine, the engine to chassis which the negative battery cable is connected to. This is why in the resting state you show 12 volts across the 2 large side terminals. The meter in a very minute way(milliamperes) is actually trying to energize the starter and turn it but the amperes required to turn it is so great that it happily gives you a voltage reading because your meter is being fed 12 volts to the red lead on the battery cable side and the circuit in the starter providing a ground to the “strap” side of the solenoid for your black meter lead. In an ideal world when the solenoid is energized and the brass washer is “closing” the connection between the two terminals this is when you would see no voltage across the two solenoid terminals.
Hope this helps you to be less confused.
Looks like soaked beat me to it, but no harm in saying it twice.