Alternator ok?

[gotmyfarm!]

On the Farmall M, the 1W alternator I put on a few years ago died. Got a new 1W alt at Napa and it seems a little bigger. This new one is touching the side of the engine... is that ok that it is touching? I never had a wire running off alt ground screw, was/is that ok? Isn't it grounded by touching the brackets and now the engine?
Also, I got a new 3W alt for the IH 666 diesel. I am going to cut the two wires and put on a new plastic 2 pin connector that plugs into alt. Since I'm cutting wires anyway, would a diode be a good idea somewhere? Or not needed?

 

[used red MN]

All good on the M, grounds through the mounting
bolts. On the 666 for the two wires does it have a plug
that is the same configuration as the one you show on
the M where the black plug is? The spade terminals in
the alternator are arranged like this - - ? Or is the plug
rectangular or square and terminals arrange like this I I
? If the same as the last your tractor has an external
regulator and you CANNOT simply swap the wires to
the plug of a internal regulator Delco 10si. If the latter I
will come back later to explain. I will attach a simplified
diagram of what you need for a Delco 10si 3 wire.
Oops, you have a diesel, so about the only thing this
diagram shows you is how to install the diode. There is
a way to use the wires that go to the external regulator
alternator if that is what your tractor is equipped with.
If you need that I will have to search a little to find the
post that explains this. It requires changes to the
wiring at the external regulator.
Simple Delco 10si wiring

 

[gotmyfarm!]

-used red MN, thank you. They go like this - - .

 

[gotmyfarm!]

red MN, yes, it is the plug where the black stopper is on M. The alt for the diesel 666 is part 213-4011, which I believe has a built in regulator.

 

[Fred47M]

Not sure about the touching part, but I
just put the same alt on my M and it
doesn't touch and still have a half inch or
so to squeeze a finger between it and hood.
So maybe a slightly longer belt to adjust
it out?

 

[gotmyfarm!]

Post-Fred47M, thank you. Yes, I had the same thought about longer belt. We must have different mounting brackets. I have one from Steiner.

 

[used red MN]

To be clear the wiring plug for the alternator on the tractor is also like this - - ?

 

[used red MN]

All is probably good on the 666, it looks like they came out with internal regulator alternators per reference of a wiring diagram. So should be no change just install the new plug keeping the terminals wired as original. The diode is already in the stock wiring. Sorry for the confusion, I just wanted to make sure it operated properly when you finished. The production dates I have for the 666 is 1972 - 76. For GM vehicles that used Delco systems 1973 is when the switch was made to internal regulators. Rarely did tractors update technology before autos.

 

[gotmyfarm!]

used red MN, oh, there is a stock diode already in wiring? Well, that would be lerfect. I didn't know that. Yes, on the alt on 666 is like this - - . I cut off the bad connection. Stand by for photo. Thank you so much.

 

[gotmyfarm!]

Bad wires at plug in part.

 

[gotmyfarm!]

-used red MN, I believe mine is 1975.

 

[BarnyardEngineering]

(quoted from post at 08:36:03 06/20/22) used red MN, oh, there is a stock diode already in wiring? Well, that would be lerfect. I didn't know that. Yes, on the alt on 666 is like this - - . I cut off the bad connection. Stand by for photo. Thank you so much.

The tractor was already wired for a Delco 10SI alternator, so if that is what you put in (the terminals are - - as you stated, so it's a 10SI), then just put the new connector on and go to work.

 

[caterpillar guy]

o If you put the excite wire to your key switch, so it is off when the switch is off, and on when the switch is on, you don't need to fool around with diodes. They are just to make sure the circuit is off when you stop the engine and not run the battery dead. The Key switch deal does the same thing and is just as simple or simpler to me. This would be on your 666 As for the M you either need a diode or a shutoff switch for the same thing. We use a switch since you need to break the circuit when engine is off. It will also disconnect the spark to the coil when shut down. The same switch can be used for both and no diode needed again.

 

[gotmyfarm!]

"BarnyardEngineering, ok, thank you. I just picked up the new connector, so will get that on and all should work.

 

[gotmyfarm!]

-caterpillar guy, thank you. ok good, key off = same as diode. On M, there is not a key, but I call it a button. A switch I guess, that I pull out before starting, and push in to shut off tractor. Is that the same as a key as far as not needing a diode?

 

[riverbend]

I thought about this when I was having trouble with the alternator on the 350. The coil and the exciter would be both on the same side of the switch. Wouldn't the coil be a path to ground when the ignition switch is off and the points are closed ? Or is the resistance of the coil enough ( like a small light bulb ) to prevent draining the battery ?

 

[used red MN]

Makes no difference to what ..got my farm.. is doing but the last part of Cat guys post needs clarification. To wire both the ignition and the excite circuit through a switch the switch has to be a double throw or double pole switch. Which in some cases the ..accessory.. terminal of a key switch is. It separates the circuits in the switch and is accessory is powered when the key is in the on position to power the ignition. If the excite circuit and ignition circuit are together WITHOUT a diode, resistor or indicator lamp in the excite circuit the engine will continue to run when the ignition is turned off and will run the battery down as it sets if you kill the engine by some other means like clutch out in high gear. This is plain and simple no way around it except with an oil pressure activated circuit.

 

[gotmyfarm!]

The M is all put back together. One more question. I noticed there are big cracks and holes on both sides of manifold. See pictures. Is that ok or normal, or is that a problem?

 

[BarnyardEngineering]

That is where the intake and exhaust manifolds come together. It's just an external gap.

 

[gotmyfarm!]

Ok, good.

 

[used red MN]

Yes, heat, sun, vibration and that radiator fan blowing
up there can do a number on those wires. On the M
maybe you have it together already but what is the
approximate diameter of the back case measuring
across the back bearing housing. If it is a 10 si it
should be 5 to 5 1/8 inches. I really think they sold you
a 12 si. Generally the outside diameter of the back
case of a 10si has 1/4 inch wide notches or ribs around
it. It will do the same thing it is just a higher amp
alternator and is a tighter fit under the hood. If it is
rubbing the valve cover after you get an hour or so on
it I would just tighten the belt a little more so there is
no chance it rubs a hole through it. And for giggles I
may as well give you the wiring diagram link, just make
sure you look at the one labeled correctly for your
tractor and engine. If you know how to shorten the web
address you can get yourself back to a page that
offers diagrams for quite a few IH models. Because YT
sells manuals, I do not like to post the link to the whole
shabang here. Hope it all worked out for you.
Wiring diagram

 

[used red MN]

Riverbend, I know you were replying to Cat guy but here goes. If you look at my reply I may have misstated how it actually works. I believe once the alternator and engine stop the voltage supply to excite circuit in the regulator actually drops off. And is disconnected some way from creating a draw. So that part of my reply is incorrect. The problem comes when a 3 wire alternator is installed with both the 1 and 2 voltage regulator spades wired together over to the output terminal. Then the alternator will excite and charge, but when shut off the constant feed to the excite circuit will draw the battery down. Sorry, for the incorrect details.

 

[Janicholson]

The push pull ignition switch will not keep the alternator from supplying voltage to the coil. The #1 terminal provides 12+ volts to the system
when running, and has plenty of power to supply the ignition coil. So it won't shut off. Putting a 10 ohm resistor in series with that wire
from #1 terminal to the coil will work. As will a clearance light bulb in series, or a diode in series with the band or bar end of the diode
toward the alternator. A standard Automotive ignition using that alternator supplies the excite voltage through the idiot light to #1 terminal.
It is in series, not to ground. Jim

 

[Jim.ME]

In the original post it was said a new 3 wire alternator was acquired for the IH 666 diesel and gotmyfarm! was looking at replacing the plug. If it had a 3 wire before, had the plug for a 3 wire, and worked in the past; replacing a bad plug for the 1 and 2 terminals should not be an issue. If it was running a 3 wire alternator it already had a diode, resistor, indicator light, or was otherwise configured to work with a 3 wire. Unless gotmyfarm! has rewired something why would it require more than replacing the defective plug connector? I will admit to not knowing if the 666 has a mechanical or electric fuel shut off, but if it is mechanical back feed from the alternator is not an issue as far as keeping the engine from shutting down.