Probably a 10DN series alternator. As suggested replace with a 10SI, (Systems Integrated)  internally regulated type and do away with the external regulator circuitry. Later models are one wire only and utilize self excitation to vary field current. Check for "cut in" rpm as I've seen many not start charging till the engine is revved far too high for my liking. They are fine once the exciter circuit is enabled. 

If you have an ammeter you will be set and if not, one can be incorporated easily enough.

If is on a Allis make certain is a Proper to the Alternator Ground(NOT Pos Ground unless marked such).  Tractor can be swapped to N Ground easily.

this is the diagram i use... I have a double poles switch to turn the alternator ON and UNGROUND the MAG at the same time... If you have a COIL, you want to turn the ignition OFF and the alternator OFF at the same time.. same switch..

this !!!

Yes it’s already swapped to positive ground

TO---> positive ground ?????

NO,NO,No !!!

BIG problem there..

99.44% of ALL alternators are NEGATIVE ground

Be 100% sure the -ve of battery is grounded.

Please report back once you've confirmed

Thinking of tossing one of these on 185 and be done.  Simple like trucks ran for years just less amp and money.

re: Yes it’s negative ground

whew !! Knowing that some old tractors were +ve ground, this had me concerned as it could explain the 'dead' alternator....

the resistor (or idiot light, or switch) is used to 'sense' power needed. I like the idiot light as  it'll come on, with engine off...turn off while charging AND if the fanbelt breaks it lights up !

I've done that with the 10SI series for well over 20 years myself. Easy way to tell if the fields are energized or not is to simply see if a bolt or something steel will stick to the back of the alternator case near the rear bearing. If not, it's not going to discharge anything. If the alternator is charging, the bolt will firmly anchor itself to the case.

Jumpering from the the B+ terminal on the back to the rt. terminal, (looking from rear) will turn the alternator on but the engine rpm and internal voltage usually need raised to forward bias the internal diodes to conduction. The left terminal is only there to assure conduction starts at low engine idle speed, (IMO).

I have never tried what you saying, but i take your word for it that it works. .... but i cant explain why the battery dont drain ?............ if the charge rate is well regulated and your battery life is acceptable, then you have SUCCESS !

I had been told many years ago the battery would drain also but it's just not been my experience. Without alternator rotation, there is not enough forward bias, (voltage) on the cathodes of the rectifier diodes to turn them on so they are an open in the system electrically. Again this can be proven with a bolt against the rear of the case. Also with an ammeter inserted in series between the B+ terminal on the alternator case, and the wire itself. I do not prefer inductive clamp on meters to measure DC current in low levels and always go in series to measure DC current.

It takes much less current to keep a circuit energized than to initially power it on. This is why one has to increase the engine rpm to raise the internal voltage and field excitation current to bring the system to a "charging" state. The engine rpm can then be reduced and the system remains operational supplying operating current.

Again my thoughts on the open terminal are it's there to provide an initial surge of voltage at very low engine rpm to get the alternator into it's charging state as soon as the engine starts.

   

No. I would order a diode bridge for your alternator and replace only that. The alternator comes right apart with four machine screws and the rectifier bridge is fastened into the rear end bell. Books for the procedure are easily obtained and most any service manual will show the process. If you only have a blown diode and the unit otherwise works well, it's worth working with. Might also install a set of brushes and clean up the slip rings while in there.

Once off the engine give the unit a simple rotation test listening and feeling for bearing noise, binding, or unnecessary effort to spin it over as they should turn easily. Only the brushes are riding on the slip rings and of course the rotor in it's bearings is the only resistance. Give the bearings some fresh grease when putting it back together.

 I know lots of folks use the ONE wire alternators, but I don't like em as most of them have to rev engine up too high to start the exitation for it to start charging. Just my choice. 

 That;s a good dwg Steve has posted, nice and simple. I like to use a universal 3 position ignition switch ( OFF-ON-Start) on everything,,remembering that for a backhoe/loader you prolly ain't ever gonna need headlights, tail lights or signal lights,,but ain't difficult to add on with a simple On-Off toggle switch.

 I cut all the hundred year old wiring out and re-wired with a universal ignition keyed switch and the simplist writing set up you ever seen,,,but it starts every time,,,,,

'ticking' might also mean there's corrosion or 'bridging' in the alternator. Something like  a buildup of dust,mud,salty water. Used to get alternator 'problems' after going offroad in my CJ-5. 'Cure' was to CLEAN the muck out of the alternator,dry it off real good.

May not be your ticking cause...just one I found out decades ago..

DJ's right, get rid of 100% of the old wiring ! You could have 2 krappy old wire, chewed insulation, funky grounding...... always best to start clean...

Yes, conductive "tracing" has always been a problem in mobile equipment alternators due to the varying and sometimes harsh environment these units live in. That alternator could also have a filter capacitor having changed value, or opened up. I've seen this cause radio interference and gauges to act erratically in the past.

Not to hijack the thread but I'm doing the same with my 11B dozer. It currently has a 20amp "DN" series alternator, and I've purchased a 60amp 20SI series to replace it. Both use the SAE J180 mount so will be a slip fit. I'm also going to do away with the current wiring loom and external regulator citing age. Although it is a 24V system, the theory is the same.

If you jumper the B+ terminal to the rt terminal and start the engine, rev it up, then place your voltmeter +, (positive) lead on the B+ terminal, and the -, (negative) lead to the alternator case you will get a reading. If it is 13.5VDC to 14.5VDC the alternator is charging the battery fine. Shut the engine down and recheck again and you should have between 12.2VDC, and 12.8VDC with no load on the system. This is static battery voltage in an unpowered state. A typical multimeter will not handle the current the alternator is capable of producing and they are usually limited to 10A. Unless a higher end multimeter, this portion is unfused.

This is of course assuming you do not have an installed ammeter in the dashboard panel. If so just look to see if that indicates a charge condition after you install the jumper wire.....

oopsy !

Then number 1 goes straight to a little light which is grounded through the housing. !!!

OOPSY !!!

One end of the light goes to the #1 tab of the alternator, the other end  goes to the switched side of the ignition switch ( same as the 10 ohm, 10 watt resistor in the drawing just above.....)

The light has to be 'floating' NOT grounded. Typically the light will be a plastic shell, with 2 black wires coming out of it. The  'nice' ones FIT into the lower ,left hole  of a D-14 dash..which for the life of me can't member what it's really for....

charge 'rate' depends on battery 'condition'

Normally just after starting ammeter will swing up to say 30 amps, then slowly move down to just above zero over a few minutes. It all depends on several factors but that's the  gist of it.

IE: '30' isn't a hard and fast number. A more powerful alternator can supply more amps,  a good battery doesn't need many to 'top up', RPM is a factor, slow=less amps, fast =more(but  limited),air temp, cold is bad for batteries,warm is nice,wiring is a BIG factor,clean new cables are BEST,old,corroded bodged are bad.

You should run the tractor, 'high idle' for at least 10-15 minutes to get a good recharge of the battery,especially in winter.

A volt meter should be reading after the regulator, so yes, it will show your 14+ volts when everything is working correctly.  

hmm, somehow I thought it was all back to 'original'....

ok, voltmeter... will read '12" with key on, engine off... '14' while charging',,lil less when done for the day... maybe '10' while starting

why the spelling ??? cause he guy who created the name, had just drunk 5 beers and had to go take a 'p'........

No need. We learn and that's the important part. 

so....

a 1 wire unit HAS those 2 tabs ??

That's crazy,hopefully '1' and '2' are NOT connected inside somewhere....

YEA... i have seen the "PLUG" on the 1 wire alternators.. BUTT... should be marked on the alter or the BOX !

re: This isn’t what I asked for.

Perfect reason to take it back and get what YOU wanted.

It , THEY sold you the wrong alternator doesn't matter that is 'works', They're fault, THEY should exchange for the CORRECT one.

I know they'll say 'sorry, it's electrical..no refunds/exchanges'......BS....

If they pull that

 say ..

well.. if you'd gone to a Chevy dealer said you wanted  a 'vette, paid ,then it was delivered to your place, you'ld be happy that it's a CHEvette  and not the CORvette you 'expected' and needed and wanted ???

bottom line ...1 wire alternator is NOT the 'SAME' as a 3 wire, not what you want,need or ordered.....

BTW, it senses internally which isn't perfect  as it can't compensate for battery lead losses.

It appears what you have now is what Codger has been saying... The #2 wire is HOT as jumpered to the BAT lug on the back.. I still dont understand how it does that without the "signal" #1 wire, but apparently it does... Wiring on these must be slightly different INTERNAL than the originals in 1970.

The 10SI with it's internal regulator was quite a cool 'gadget' when it came out.

The engineers who did the regulator's solid-state design started with a very blank slate.  They had a rotating armature with slip rings, and a field, just like any other alternator.  They knew that they could regulate current through the field to control output voltage on the surrounding windings.

They knew that the surrounding windings' voltage presented a perfect signal to use as feedback to control the field.

They knew that the case would be aluminum, and there'd be a fan to force airflow, so they could mount a solid-state regulator directly TO the frame, integrated in, it would perform as an excellent heat-sink.

They made the regulator to read internally, and sink heat through that frame.

They also knew that, since the armature would be ferrous, it would develop a little bit of magnetic 'memory'... as generator guys say "Residual Magnetism".

When you spin a coil within a magnetic field, or you spin a magnetic field within reach of a coil, The coil presents voltage, and if there's a place for that voltage to flow, it develops current.

They knew that, as long as the armature had residual voltage, it would develop enough voltage to flow current, which the regulator could divert into the field, to develop a stronger current, which would create a stronger field, thus yielding a 'self-exciting' alternator.

The only circumstance they could NOT accomplish, is developing residual magnetism in that armature, if there was none to begin with... and since some machines and vehicles sit for long periods of time, an external source for a little 'seed' current to wake it up is necessary.  Remember how we gotta 'flash' the field on our generators?  Same deal, different meal.

This is no different from externally-regulated alternators and generators, and in those earlier systems, engineers decided that using a small light bulb between the field and battery would 'force' the field into action when starting the engine.  Once spun up and generating, the regulator would be pushing current directly into the windings, and in doing so, the lamp would not illuminate (because voltage on the field is now equal to, or higher than the battery's voltage, right?)

The cool side-effect, is that if the alternator stopped alternating (a broken belt, for instance) that light would illuminate, because the field current would no longer be internally-generated.

When the Delco guys developed the 10SI, they wanted to make it absolutely foolproof (which isn't possible, because the only thing that develops faster than technology, is foolishness), so they settled for ALMOST foolproof.  They added that lamp 1) so that people now accomplished into expecting idiot lights would be satisfied and 2) in the event that someone doesn't drive their car for a week or so, it'd still wake up and operate.  As a result of the 'always had a BATT Light', Delco's engineers made the SI's regulator WITHOUT the internal connection for self-excitation.  The alternator would do it ANYWAY, if spun up fast enough... and nobody knew the difference.

SO, you can put a one-wire alternator on just about anything... as long as you spin one FAST ENOUGH, they'll self-excite without that lamp.

IF you have a low-output version, they'll self excite without any fuss.  My D17's 10SI is wound in series, with extra turns on both field and armature, and it wakes right up on every start, even if the throttle is at dead-idle... but due to the windings' added turns and smaller wire, it doesn't knock out much more than about 27A.  Since I use the tractor for a few hours every week, and I'm not running a thump-beat stereo (there's 2 medium floodlamps and 2 small LED taillamps, and an ignition coil), that battery is ALWAYS good, even if it's at dead-idle speed.

If I were to put a 55A unit on it, I'd start having problems... because 1) it wouldn't self excite until throttling it up a bit and 2) I'd be running it too slow to really do well.

IF I put the high-snot 100A on it, it simply wouldn't do the job... it might self-excite, but to get that kind of output, they have to wire the stator up for parallel (delta) rather than series (wye), so it takes even MORE spin to get above 14v on the output.  Since I use this tractor for creeping trailers around, toting pallets on forks, I rarely run it up past 2/3rds governed limit, when I do, it's because I'm running 4 miles down the hill to help my Dad, mebbie I make that run twice a year... it would simply NEVER charge it's battery.

You COULD run that alternator in one-wire.  On the original 10SI, there were SOME regulators that didn't have the internal connection to self-excite... but it didn't take long for the aftermarket to integrate the internal connection ANYWAY, because a failed BATT lamp would cause the alternator to not operate, thus, drain a battery.

I am remembering buying a 2 wire plug with pig tail and putting both to one wire going to the battery. I know I was amazed at how simple it was.  But who knows what I am forgetting. The one that I know still works does have switch.  The crawlers did not but are parked as I do less and less farming.

So give it a little time. Keep a eye on battery condition to see if it is drawing juice when just sitting. You said it was charging when you first put this last alternator on.

Another quick test is to use a non contact thermometer, (or your hands) and look at the alternator temperature when the engine is cold such as sitting overnight. If the alternator is very warm, it is drawing current and that current is from your battery.