Wiring Delco alternators

one wire delco Alternators ,Seems to be the only GM ever built worth putting in service ,.. Why Bother with original wiring ,, simply wire direct to the battery seems to wrk fine?,,, is there some pelosi law agaisnt that ???,,...

Two things wrong with that. connecting a 1 wire alternator directly to the battery, cuts the ammeter out of the system, so you have no indicator to tell you the alternator is working.

Direct alternator to battery is only good if you equip the machine with a voltmeter to indicate charge or lack of it.

If you have a machine that uses an alt / gen light, then you still need to connect the #1 alt terminal to the light to get a charge / no charge indication.
If the machine has a charge indicator light, you can connect it to a 1 wire alternator, but it will perform no better than a stock 3 wire alternator. You still end up with a two wire alternator which is what a 3 wire is when you connect the #2 sense wire directly to the BAT stud on the alternator.

99% of the one wire set ups need 2000rpm plus to kick them in and that on a cold engine is a no no plus most tractor engines do not spin up that high is again not good

I had an externally regulated alt on my a that had problems. I would like to put a delco on but do not have a light. What would I hook the three wires to. I know there is the battery and you can run the other wire to battery terminal but what does the third wire have to hook to? Can you just leave it off?

#1 wire to switched 12V with either an indicator light or diode inline, #2 to the BAT stud on the alt rear.
A wire from the Bat stud on the alt to one side of the ammeter, with the battery connected to the other side. Connect any ignition, lights or other accessories to the same ammeter post as the heavy alt BAT wire.

One of you other guys please post a wiring diagram for a Delco 10 SI conversion.

http://www.ytmag.com//articles/artint195.htm
Delco alternator wiring.

"Seems to be the only GM ever built worth putting in service."

Trouble with your theory is that GM DID NOT build those units. (They DID build bigger, heavier-duty one wire units for HD truck, Ag and Industrial service though.

The 10 SI and 12 SI "one-wire" alternators are aftermarket perversions of alternators that were originally designed and manufactured by GM as "three-wire" units.

So, you can't roghtly PRAISE (or BLAME) GM for the light-duty "one-wire" units that are products of other companies!

The only thing I find "good" about the 10SI and 12SI Delcos is they can be found cheap, if you are a good scrounger. I rarely pay more then $10 apiece. An aftermarket self-excite regulator cost another $12, so these "one-wire" units can be had for $25 or less.

Downside to automotive-spec. Delco 10SI and 12SI alternators is their large size/diameter, poor rear bearing support, and lack of dust protection for farm use. Any of the so-called "one wire" units I see for sale, advertised for tractor conversions are Delco spec "100", which means "standard light duty", i.e. not meant for tractor use. Fine for collector tractors that don't get used much. Use it on a full-time use farm tractor, and dust does them in pretty fast unless they get a dust-seal kit added.

For those stated reasons, I've been using little Hitachi alternators for years - mostly off of 80s-90s Subarus. Much more compact, all ball-bearing supported, AND sealed. A much better unit.

Delco does make some good small sealed alternators on later cars and trucks, but they aren't always cheap. The CS series has full ball bearing support, is more compact, and better sealed then the older 10SI and 12SI units.

Some Delco specs:

Farm rated Delcos - 10SI type 116 and no 12SIs

10SI comes as 100, 116 or 136 ,14 pole. 6.6” OD by 7” deep, metal fan

61 amps at 6000 RPM and 0 amps at 1600 RPM
72 amps at 6000 RPM and 23 amps at 1600 RPM

12SI comes as 100 only ,14 pole. 6.6” OD by 7” deep, plastic fan
66 amps at 6000 RPM and 30 amps at 1600 RPM
78 amps at 6000 RPM and 30 amps at 1600 RPM
94 amps at 6000 RPM and 30 amps at 1600 RPM

Delco types:
100 is light duty only and three-wire hookup (or two wire), 5/8” shaft
102 is medium to HD, totally enclosed, and in 1 or 3 wire), 5/8” shaft
110 is flame resistant and 1 wire hookup, 5/8” shaft
116 has special brush holders, 1 or 3 wire, and an tach terminal, 5/8” shaft
136 has special brush holders, 3 wire hookup, tach termial, and 7/8” shaft

Do you have a part number for those Hitachi units? Are they internally regulated?

I have always had good luck with delco's cause they are so cheap. Its easy to justify keeping and extra on the shelf for the sunday repair jobs. I need one (12v alternator) for a farmall H and a smaller unit would be easier to mount under the hood.

Yes, Delcos are cheap and that is their biggest asset. Cheap and easy to work on. They are fine for limited use tractors unless size is an issue.

Deere tried using Delcos OEM for awhile. But even with the brush/dust kits added, they had short lives. Also lost their diode-trios pretty easy when tractors got "boost" charged. That's why Deere tends to use Bosch, Motorola, or Denso sealed units.

The Hitachis are interally regulated, just like the Delcos. They even have the same regulator bypass port that you can stick a nail into to make it bypass the reg and run max charge (for testing).

I don't know off hand what specific model Hitachis I've been using. Most are the 5" to 5.5" diameter LR series, probably LR-150s or LR-170s. I've been driving Subaru Loyales for years - and have scrapped many due to rust. Thus I have many extras laying around. 1985 to 1992 Loyales and GL series all use them. Subaru Justys use smaller versions that only measure 4.5" diameter. Many Nissans, Isuzus, etc. also use the same.

I'm in the rust and snow belt in NY, so junkyard alternators from Subarus were just as cheap as Delcos. But now, not many older cars in the local junkyards anymore.

I forgot to mention that the older and smaller Hitachis and Nipppdensos are now cloned by Chinese makers. They are often sold as "forklift" or "compact tractor" or "caterpillar" alternators. Very compact (around 4.5" diam), and come with V-belt pulley - often brand new for $75 (not rebuilt).

A few examples:

http://www.dbelectrical.com/p-5801-new-alternator-john-deere-tractors-skid-steer-yanmar-and0197.aspx

http://www.dbelectrical.com/p-3654-toyota-forklift-lift-truck-alternator-27060-78003-100211-4540-and0168.aspx

The only good thing about a one wire alternator. Is that it sometimes provides a somewhat functional charging system. That is a step above using the 120v charger every night while parked in the shed. By somebody with zero electrical knowledge for a few bucks.

The Part # for the HItachi Alternator is 14231.
I get mine from O Reilly Auto parts. There core charge price is $7.50 plus low price. about $50.00
Napa also has the Hitachi Part #2138130 Core charge a little bit more.
Good Luck