Nuffield Universal 3 Wiring Overhaul

KlemKadid

New User
Howdy folks, new to the forum here so pardon me if Im overstepping any edict or rules.

My question for you folks today is along the lines of the electrical components of the Nuffield Universal 3 tractor.

Ours in a nutshell, has none. and while she starts like a charm and seems to run pretty well, after 14 years in the previous owners hands having never gone through so much as an oil change, I fear were merely hopping on and crossing our fingers everytime we try to start her up, and im lookin to change that.

Im a Carpenter by trade, and am fairly new to the world of tractors, electrical & engine repair entirely, although I did manage to fix our snowblower rolleyes , so I wouldnt say im a complete nub around tools and machinery, and im a pretty quick learner if I say so myself wink

None the less, Im currently in the process of starting off slow and working solely on getting the lights up and running. Now as ive mentioned, our tractor is pretty bare bones, and while looking through the manuals wiring diagram a few times Ive come to the conclusion that we have no 'control box' or alternator regulator as, if im correct, it is modernly called. nothin behind the guage panel, where its supposed to be, cept some worn out wires. The starter solenoid hooks directly to the battery as does the alternator, both being on the same terminal.

now from my own research, it seems some of the newer alternators have the regulator attached already, and while ours definitely isnt the original dynamo nuffield slapped on there, it certianly isnt the newest looking piece of equipment, still gotta check the dates, but say it is one of them newfangled ones, how would one go about wiring in a control box? or would one even need to?

I guess what im tryin to say here is that were lacking a control box, and from what ive read, it seems like its somewhat of an important piece, but assuming that the alternator we have on now has one attached, would there be a need for installing a seperate one? or would we just have to wire everything through the existing one.

cheers
 
Not exactly sure, but most alternators don't need the control box (voltage regulator), the original tractor was fitted with a generator not an alternator, the generator needs the control box... If someone has swapped the generator for an alternator they may have removed the control box too. It should be mounted on the fight side of the tractor just under the battery box, black box about 2 inches by 4 inches...

You shouldn't need one for the alternator, I rewired my old Nuffield 10/60 for an alternator, it is a fairly easy job. I have a feeling their maybe new wiring harness available but they could be spendy.

Email is open.
 
Klem, I searched the net typing in 'Nuffield tractor wiring diagram' and came up with a few wiring diagrams on the first page. I don't know what model yours is but one of the diagrams I clicked on is very simple and shows the starter, dynamo and control box along with the ignition switch. Try searching through the selection of diagrams and see if one of them matches your tractor.

Sorry I can't give you any other information but I know nothing about European designed electrical systems aside from what I read on the net. Jim
 
(quoted from post at 14:18:56 01/02/16) If someone has swapped the generator for an alternator they may have removed the control box too. It should be mounted on the fight side of the tractor just under the battery box, black box about 2 inches by 4 inches...

I think on the Universal 3 its mounted behind the guage panel as per this image

http://i55.tinypic.com/2vci8ax.jpg
(from the leyland nuffield forum)

compared to my setup;
same spot, on my tractor
20160102_162454.jpg


spot mentioned under battery on my tractor.
20160102_162547.jpg



You shouldn't need one for the alternator, I rewired my old Nuffield 10/60 for an alternator, it is a fairly easy job. I have a feeling their maybe new wiring harness available but they could be spendy.

Im not too much concerned as to the wiring of the alternator, as it seems to work fine, as much as the wiring of everything else, the ammeter, horn and oil pressure all seem to eventually run through our missing control box.
 
I cant seem to edit my post atm to add this in so ill mention it here for now

my main question is how would one wire in the guages? The ammeter, oil pressure and horn circuitry all run through the control box in the schematics, but considering I do not have one, would I need to order one or is it possible to wire it to the alternator/the alternators regulator.
 
If the alternator is wired directly to the battery, the amp meter has been bypassed. At this point, probably the easiest thing to do would be to replace the amp meter with a volt meter, wire it to the ignition side of the ignition switch.

Since it is charging and no problems exist, there is an internal regulator in the alternator. If there were no regulator, the alternator would be getting hot, battery boiling dry, belt burning, etc, lots of obvious problems. A volt meter would tell you this.

The other gauges, temp and oil, are mechanical and have no electrical requirements.

Rewiring a tractor is simple. Just replace one wire at a time, trace down the dead ends and abandon them. The lights would power off the battery cable at the starter solenoid/switch, same place the alternator is connected.

Welcome to the forum! Ask all the questions you want, answers are better than mistakes!
 
The voltage regulator was used as a sort of
terminal box, everything connected at the
posts of the voltage regulator... The oil
pressure gauge is mechanical (original) and
just has wiring for the back light...
Ammeter would need to be wired in backwards
as now the tractor is neg ground...
Otherwise gauge will read backwards.if you
are rewiring just solder the required wires
together and insulate them instead of using
the control box, with an alternator there
is no need for one
 
So I took the wiring scheme that a user on another forum gave me

http://www.thenuffieldandleylandtra...agram Nuffield 3-45 and 4-65 - Alternator.pdf

and made an attempt to try and exclude the things I didnt want while maintaining the integrity of the circuit. Anyone mind taking a look and pointing out where ive gone wrong?


Legend
1.Alternator
2.Battery
3.Starter
4.Ignition switch
5.No Charge light
6. Voltmeter
7.8. & 9. Disregarded
10. Horn Button
11. Horn
12. Disregarded
13. Disregarded
14. Flood Light
15. Rear light
16. Light Switch
17. Panel Light
18.19. Disregarded
20.21. Side lights
22. Headlamps

Wire color scheme remains the same as original schematic
 

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