Farmall A electrical

bluesman302

New User
Is there anyone that can explain how to wire a Farmall Super A?
I am new to this hobby, and need some help.
I received a Super A that was in bad shape. I made sure she would crank over. Then started reassembly. The tractor didn't have a generator, regulator, or solenoid or battery, or any wiring. I do have a couple of Delco Remy 10si alternators, an automotive style key switch a neighbor gave me that looks new, a 12 volt coil with inside resistors,diodes, warning lights, a 4 post solenoid 12 volt, and a new spool of 10 gauge wire and 12 gauge wire.
I started wiring tractor like a lot of diagrams on internet show, but I get no response. I have tried everything. I checked resistance on all parts and wires, had alternator and starter tested, but I don't have anything. What am I doing wrong?
Is there anyone that may live in Akron,Canton,Ohio area that I may talk to?
I would greatly appreciate any help.

Thanks,

Gordon
 

if you are having trouble wiring this tractor, you may want to step back and do one system at a time.
For example, just hook up the wire for the positive side of the coil to the ignition switch and to the battery only, make sure you are getting power to the coil before proceeding to the next circuit. This is a really simple system, but for people that are not electrically-minded it is better to work with each circuit individually and confirm that it is working before going to the next.
You could even getting it running without the alternator hooked up, just to verify that the ignition circuit is working before you add in the charging circuit.
 
Need to back up a minute and ask 2 questions. Does your tractor have a magneto or a distributor. After that what to you want for an electrical system - original 6 volt system or a much more modern 12 volt alternator system. After that we can tell you how to wire your tractor.
 
From reading the post I gathered that it was distributor, not magneto because he said he had a 12 volt coil, which that with the fact that he said he had a 10si (12v)alternator and a couple other references to 12 volt items, it sure sounds like he is wanting 12volt system.

Pretty much 12volt from battery to ignition switch common, 12 volt from run to coil +. - from coil to points/condensor. Start from ignition switch to excite (small terminal) terminal on solenoid. Battery to big lug on solenoid. other big lug on solenoid to starter lug (which will be tough if its original starter, that doesn't have a lug)

That would get you running and starting. From there work on charging circuit. which is different for 1 wire or 3 wire 10si. But both simple. Get that working and then post back.
 
#1 no coil will have an inside resister or diode or warning light no such thing.
#2 the ignition circuit is so easy I can wire them in my sleep but I was also at one time a Navy E.T. so wring is Childs play.
So that all said if you use a key type switch you need a wire from the battery of amp gauge to the battery post of the switch marked B on most. Then a wire form there to the coil and it your using an alternator then the + post on the coil to ignition switch. The starter on your tractor should have a saddle type starter switch so that should be a no brainer there since the battery cable hooks to that switch. But that switch can also go bad so that could be part of your problems. I've wired so many tractor from the ground up I can do it and not think about it
 
I've never been a Navy ET, but I have wired lots of tractors from the ground up, as well as numerous vehicles, houses, shops and electronics and taken numerous electrical engineering classes and Ignition coils definitely have different primary resistance values and there are there made to run 12V without an inline resistor.

Do some research on it.
You can measure primary resistance on an ignition coil with a simple multimater. They are anywhere from 4.0 Ohms down to .35 Ohms
 
General rule of thumb
~3.0 Ohm resistance 12volt coil
~1.5 Ohm 6 volt coil
Outside of these values are for performance/electronic ignition systems.
You add resistance to a 6 volt coil to raise the resistance down to keep the amperage in check for 12v.
For example: 12 volts/3 ohms (coil) = 4 amps 6 volts/1.5 ohms (coil) = 4 amps
 
I own 3 VOMs and I have just for the heck of it checked coils for resistance and not one of them agrees with the resistance. Or in other words the VOMs the common man has the resistance is a ball park reading at best. To get a real/true reading one needs a calibrated VOM and they need to be recalibrated from time to time. So while what you say is likely to be true the common man is not likely to see those type of reading with the common VOMs most people own
 
I have some cheap Meters and some very expensive ones and they all ready very close when checking a coil. It doesn't have to be exactly 3 or 1.5 ohm. I used the ~ to mean approximate. Preferably it would be slight over 3 Ohm to 4 Ohm for 12 volt oil and slightly over 1.5 Ohm to 2 Ohm for a 6 Volt coil.

The 6 volt ones I have measure around 1.6-1.7 and the 12 volt ones measure 3.2-3.4
I have a few performance coils to be used with HEI conversions I have done and they are .7 Ohm.
This is measured with a high end Fluke meter and a cheaper harbor freight throw-away meter.
 
I've owned a cheap HF VOM for years and it still has the battery that came in it when it was new. The battery indicator is saying it need to be replaced so I will be doing that soon. I also have a VOM from TSC and well it is pretty much only good for telling you that you have voltage or ohms since when you touch the 2 leads on any ohm scale you should get zero and it never zeros out. I am also us to the Simpson 260 we used when I was In the Navy. I was a Electronics Tec. Computer and was micro mini qualified so soldering. But that was 38 plus years ago. Back then I worked on computers that where as big as a refrigerator.
 
I have a Simpson 260 and loved the analog meter for testing switches and pots, watching for blips in the needle, signifying a dead spot. It was also very nice to be able to zero it before measuring resistance. It finally crapped out on me and it's somewhere in a cabinet or attic in the garage.
The day that it crapped out, I was in the middle of troubleshooting and went right to another meter. I set it to the side and haven't looked at it since. I could probably pull it out and fix it if I can find it.
I really like tinkering with electrical and electronics and even got my Extra Ham license, but it seems that I don't mess around with it as much as I used to. I have too many tractors to work on right and too many service manuals to write. :)
 
I stepped away from electronic a long time ago. Got to the point I hated working on the stuff any more. But back when I was a lot younger I messed with it a lot. Us to pick up old TV sets and repair them and then sell them. Got most of those old TV for nothing and used parts from a few to make one good one but that was back in the 60s and 70s and they where mostly tube type. I had one TV once that would work till warm then die you might hit it and have it work again or it might not. I took it and unsoldered every thing then solder it back and it worked for years. It ad a lot of cold solder joint which caused the problem
 

It has a distributor. The tractor didn't come with 6 volt system. I have parts to make it a 12 volt. I am trying to keep my cost down until I see how good or bad she runs.
 
[qu
e="ih560"](reply to post at 08:21:41 07/12/18) [/quote]

Ok. Thanks. I wasn't sure how to work in this forum. Think I'm catching on.

Again thanks.
 
(quoted from post at 18:33:28 07/12/18)
Thank you . I will try this in the morning. Everyone thank you. Will let you all know what happened.

Dear IH 560.

I did as you said, and at first nothing. I pull the starter, and tested it to make sure it was still working. I grounded it and tapped the lug, and she spun. Reinstalled, and connected battery. As soon as I put negative cable to the neg. post, it started cranking over. I thought I had my wires on (small terminals) on solenoid crossed but it did the same thing. This solenoid has 2 large lugs for battery and starter, and 2 small terminals. By the way, my key switch was in the off position. I disconnected the key switch, and the neg. cable fell back on post, and she started turning over again.I guess I have a bad key switch and maybe bad solenoid, or need a 3 post solenoid.
I am not to savvy when it comes to electrical stuff. Mechanical, I'm fine. I am sure I'm doing something stupid, but just don't see it.
I am sorry if I am bothering you all, but I am trying to learn.
Again if I can get your help I will be must appreciative.

Thanks,

Gordon
 
Well first off it should not have a solenoid but if it does it does and can be made to work. If it spun over just by hooking up the battery take the wire or wires off the small terminals of the solenoid and see if it still spins over. If it does then the solenoid is bad and needs to be replaced. If it does not spin over then key switch is likely to be bad
 
If your solenoid has two small terminalls, it could be the type where one of the leads is meant to give full battery voltage to the coil when starting. If you have a 12V coil, do not hook this one up. Only hook up the other.
The way you can tell is to set your multi meter to Ohm or Cont and put on lead on each of the big lugs. Ground the body and then touch a postive lead from the battery one small terminal, watch for the meter to read Zero or Beep (however you meter is setup) indicating that it has excited the solenoid.

The small terminals that causes the solenoid to excite (pass current) is the one you want to hook to your start output from your ignition switch.
 
I meant to also answer the other issue of the starter cranking over without the key switch turned. Unhook the small terminals and see if the solenoid is still passing current. If it is, then the coil inside the solenoid is stuck. If it isn't then you have a wiring issue.
 
Most of the 4 wire solenoids I have ever seen had an S and an I on them. S was for start and I ignition for the ballast resister by pass
 
I agree that many 4 terminal solenoids do, but I have seen them both ways, where some 4 post have an S and an I terminal and where they have two small terminals for positive and ground. I remember buying one several years ago that didn't have an S and an I, so I thought for sure they where just the positive and ground for the internal coil, therefore that's how I wired it. When I hit the key, the starter turned over but it also fried the ground wire I had ran from the solenoid to ground. Since then, I always verify the terminals on a 4 terminal solenoid by testing.
 
To add to ih560, the type of solenoid found on Ford products can be internally wired in a few ways, so verification is necessary. Ford tractors prior to'65 used one that current goes in one terminal and out the other to ground. New one I got recently, name brand item, had the S and I molded on the case even tho it was wired for in and out. The units for the cars and trucks, current went in the S term and ground to the mounting bracket. So if you have solenoid of unknown origins, must check it.

Item 2 Sup A I have has manual pull rod to run the starter, so I have to be very suspect to what some one did to cob up the wiring on your tractor. That can create more problems than solved. Hang on cause we can get you thru this. If you can, go find another tractor and see how it is assembled. If I get mine out and get pix, I can send some.

Item 3 I just replaced all the wiring on Farmall A. Total of 4 wires from front of engine to electric box. 2 of them are for lights that are not there now.

Item 4 I am advocate for leaving the 6v system as the starter, if working good, does not slam the drive gear into the ring gear. Causes damage to teeth and need to replace ring gear. Dubuque 2 cyl JD really have that issue. A good clean and lube of the starter will do more to make for easy starting tractor. Think about it--how long has it been since the bushings on the shafts have had a drop of oil on them?
HTH,
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top