Ford 8N wiring

[timjcatt]

Greetings! I was gifted a 1952 Ford 8N that hasn’t run for 12+ years, my first tractor. It has a 12V conversion, side mount distributor. I’m going through all the mechanical checks, fluid changes, etc., but have some questions on the wiring. It looks there was a bit of corrosion from the old battery terminal that spilled over onto the wiring. I’ve already bought new battery cables. Harness appears intact but is now rock solid, no flex. It’s a Delco-Remy alternator with a two wire plug but one wire has been pulled off, I assume this okay as I have read out about “one wire” alternators and the tractor was running fine when parked. There is a green wire that comes out of the harness up closer to the dash that I have no idea where that goes.
My questions are, do you guys think it makes sense just to replace the wiring harness rather than removing and cleaning up all connections? There is a voltage regulator (I assume the original from the 6V system) mounted on the back side of the dash behind the proofmeter that still has wires going to it, would that still be in use with the 12V system? The ammeter reads about +12-ish when engine is not even running, does it make sense to replace that? Any other thoughts on wiring in this situation?
Many thanks, this Forum and the archives have been super helpful!

 

[HarryVanderpool]

Why do '52 8Ns attract THE WORST electricians?!!
Here is a post about mine, scroll down a ways:

https://forums.yesterdaystractors.com/threads/fired-up-the-junk-pile-today.1780519/

Get a correct wiring diagram and tear it all out and start over.

 

[HCooke]

Voltage regul;ator is not needed. I cannot tell you about the green wire near the altenator. I would think about replacing the wiring. Some make their own wiring harness. For a good wiring diagram Google "wiring diagrams by JMOR"

 

[Non-farmer]

The voltage regulator has no place in a 12 volt system. Your alternator has its own, more reliable, regulator.

Edit: lol, Harold. Talk about post timing

 

[Non-farmer]

Why do '52 8Ns attract THE WORST electricians?!!
Here is a post about mine, scroll down a ways:

https://forums.yesterdaystractors.com/threads/fired-up-the-junk-pile-today.1780519/

Get a correct wiring diagram and tear it all out and start over.

At the upper right of each post are some icons. rightmost is the post number. To the left of that is a bookmark icon. To the left of that, normally the leftmost icon not counting "NEW" if applicable, is a share icon. If you click that, you will see at the bottom of the popup window a direct link to that post. If you use that to direct people to an older post, it will take them directly to it - no scrolling needed.

 

[deanostoybox]

Greetings! I was gifted a 1952 Ford 8N that hasn’t run for 12+ years, my first tractor. It has a 12V conversion, side mount distributor. I’m going through all the mechanical checks, fluid changes, etc., but have some questions on the wiring. It looks there was a bit of corrosion from the old battery terminal that spilled over onto the wiring. I’ve already bought new battery cables. Harness appears intact but is now rock solid, no flex. It’s a Delco-Remy alternator with a two wire plug but one wire has been pulled off, I assume this okay as I have read out about “one wire” alternators and the tractor was running fine when parked. There is a green wire that comes out of the harness up closer to the dash that I have no idea where that goes.
My questions are, do you guys think it makes sense just to replace the wiring harness rather than removing and cleaning up all connections? There is a voltage regulator (I assume the original from the 6V system) mounted on the back side of the dash behind the proofmeter that still has wires going to it, would that still be in use with the 12V system? The ammeter reads about +12-ish when engine is not even running, does it make sense to replace that? Any other thoughts on wiring in this situation?
Many thanks, this Forum and the archives have been super helpful!

View attachment 118225View attachment 118226View attachment 118227View attachment 118228

1ST PICTURE That resister block below the ammeter goes to a front mount distributor
2nd picture that is not a voltage regulator. looks like a horn relay, could be for lighting
4th picture that green/blue wire goes to #2 terminal on alternator (sense), see red wire other side of plug goes to output terminal. see broken wire coming out #2 on plug that attaches to alternator.

If it were mine would start over with wiring.

 

[Jim L WA]

I noticed that resistor block too. Makes me wonder if it's an earlier tractor with a '52 engine.
Like deanostoybox said, I would rip and tare and start from scratch with a new harness.
Have fun and keep us up to date.

 

[timjcatt]

Thanks for the replies. Makes sense to me to yank it all out. Do you think the alternator should be replaced, too? If I yank it all, do you think voltmeter or ammeter is the better option?
I called that block a voltage regulator because that’s what it showed in that area on the parts diagram I have for the tractor. I agree it looks like a relay, I’ll do more wire tracing when I get back to the tractor in a couple weeks (it’s at my mother-in-law’s, a 5 hour drive away). It currently has a Wagner front loader on it with headlights mounted to the top bar, original head lights and wiring gone, rear work light gone but wiring still there. Maybe that relay was put in when the loader lights were installed?
Comment about it being an earlier tractor with a ‘52 engine piqued my interest. Any way I would be able to tell if this is the case? One thing that kind of threw me was when I rebuilt the carb. I bought a carb kit for a ‘52 but when it came to replacing the choke plate shaft the one in the kit was too large a diameter. Nothing wrong with the old one so I just reused it. The other thing I noticed is that the pictures I saw of those carbs had “Marvel~Schebler“ cast into the bowl. Mine has it cast into the flange going to the intake manifold with no ~ between Marvel and Schebler. So maybe the carb came from an earlier engine? Or am I reading too much into that?

 

[HCooke]

3 different modles of MS carbs on the N tractors. They are are all interchanable though so I would not use that to determine what model N tractor I had. You have a 8N with a side mount distributor. That is all you really need to know.

 

[JMOR]

Your picture shows original loop style AMMETER, but if reading anything but zero when battery disconnected, it is bad.

 

[timjcatt]

Found the JMOR wiring diagrams, thanks for that! So given the alternator that is currently on this, with a plug in that side port and the wire connections on the back, can I use that same alternator with just the one wire connected to the back as it shows in the diagram without frying anything? Or should I replace the alternator along with the wiring?

 

[JMOR]

I made many diagrams to fit the requestor's desires....for 3-wire 10-SI alternators, one wire 10-SI alts, generators, net reading ammeters, alt only reading ammeters, voltmeters vs ammeters, etc, so you select the one that fits what you have and want, If your alt is a one wire, that is all you need, if it is "as from factory GM 3 wire, you need all 3 connected. Can't tell visually from outside what alt you have. It depends on the internal voltage regulator. Most have a number on that VR which is an indicator of one wire or factory 3 wire, If it is one wire and connected as one wire, it will be fine, but if 3 wire and connected with only one wire, it won't charge as it should.

 

[timjcatt]

Got it (I think), thanks. Sounds like my most straight forward option for this thing to get it up and running will be to get a new wiring harness, one wire alternator, terminal block and ammeter.

 

[528N]

I made many diagrams to fit the requestor's desires....for 3-wire 10-SI alternators, one wire 10-SI alts, generators, net reading ammeters, alt only reading ammeters, voltmeters vs ammeters, etc, so you select the one that fits what you have and want, If your alt is a one wire, that is all you need, if it is "as from factory GM 3 wire, you need all 3 connected. Can't tell visually from outside what alt you have. It depends on the internal voltage regulator. Most have a number on that VR which is an indicator of one wire or factory 3 wire, If it is one wire and connected as one wire, it will be fine, but if 3 wire and connected with only one wire, it won't charge as it should.

JMOR,
I have looked up your diagrams and they have been a huge help and I appreciate your efforts to assist all us 8N guys greatly. My only question, in the case of my 51 8N with 12 volt conversion, is why didn’t you use the same color code as the harnesses, such as mine, that are ordered thru Yesterday’s Tractors and just received today. Color code isn’t close to the harness I received. (See page 6 of 8). Brown to coil, there is no brown, white to starter switch, way too long like it goes to 1 wire alternator and on and on. Would have been a piece of cake if matched, now I will have to cut the tubing and design the harness that works, according to your diagram. If I would have know this I would have just used my existing wiring that would have less issues.

 

[JMOR]

It has been many years since I did those, but I believe the colors I used were the original factory colors. After market harnesses may use anything they want.
It is possible that some sellers asked me to make a diagram using their colors?

 

[TheOldHokie]

It has been many years since I did those, but I believe the colors I used were the original factory colors. After market harnesses may use anything they want.
It is possible that some sellers asked me to make a diagram using their colors?

Can you do one in black and white for me. TOOH tells me I am color blind.

TOH

 

[JMOR]

Can you do one in black and white for me. TOOH tells me I am color blind.

TOH

Just imagine all colors are grey.

 

[Hobo,NC]

Greetings! I was gifted a 1952 Ford 8N that hasn’t run for 12+ years, my first tractor. It has a 12V conversion, side mount distributor. I’m going through all the mechanical checks, fluid changes, etc., but have some questions on the wiring. It looks there was a bit of corrosion from the old battery terminal that spilled over onto the wiring. I’ve already bought new battery cables. Harness appears intact but is now rock solid, no flex. It’s a Delco-Remy alternator with a two wire plug but one wire has been pulled off, I assume this okay as I have read out about “one wire” alternators and the tractor was running fine when parked. There is a green wire that comes out of the harness up closer to the dash that I have no idea where that goes.
My questions are, do you guys think it makes sense just to replace the wiring harness rather than removing and cleaning up all connections? There is a voltage regulator (I assume the original from the 6V system) mounted on the back side of the dash behind the proofmeter that still has wires going to it, would that still be in use with the 12V system? The ammeter reads about +12-ish when engine is not even running, does it make sense to replace that? Any other thoughts on wiring in this situation?
Many thanks, this Forum and the archives have been super helpful!

View attachment 118225View attachment 118226View attachment 118227View attachment 118228

Broken Green wire at the alt is a fuse able link that's burnt out, that's what they do when you short the wire out. Whats been called a horn relay is a relay for a light it appears to go to the rear for a rear work light.

The alternator needs to be tested they are easy as pie to test its already on a test stand you need to google how to test a GM 10SI alternator. You need to determine the alt used and amp meter are voltmeter you will use. Wiring up from scratch is to expensive for a one off I would order a wiring harness for a 52 8N 6V and modify it to use with a 3 wire alternator using voltmeter. Lights are add on worry about them later.

As far as I know there are no inexpensive wiring harness make for a 3 wire 10si alt you have to roll your own are convert a inexpensive 6V harness to the 10si. Even if you go one wire you will still be modifying the harness in some form are another. A side mount 6V harness has plenty of ways to modify the harness conveniently its so convenient its overlooked.

What makes it harder is folks have their opinion on amp meter verses voltmeter, amp meter lubbers are stuck in the past and don't understand the power of a voltmeter. Their diagnostic skills will always suck they will chase their tall forever. That's the cold hard facts why make life harder than it should be.

 

[Dave G9N]

I was going to comment on the regulator, but after reading and agreeing with deanstoybox comment that it looks more like a relay, I will just say that this may be of some general interest concerning alternators and voltage regulation. https://www.carparts.com/blog/alternator-voltage-regulation-101-with-wiring-diagrams/

 

[timjcatt]

Just wanted to “close out” this posting before I start another unrelated thread. Thanks to all who provided input. I did buy a new wiring harness, ammeter, battery and single wire alternator. I was able to get the tractor running and it appears the charging system is functioning normally. Pretty happy about that!