Re: 1971 Model 140 converting to alternator

Charlie M

Well-known Member
Looks like I see a resistor by the distributor - are you already 12V. Is your current generator not working. Give us a few more details.
 
The alternators being used from GM (Delco 10SI, and 12SI) are not specifically truck components. All GM production of cars and light/small medium trucks From the mid 60s
were SI series for many years. They are solid and reliable. Far more than the generator. Jim
 
Nice, I would tie that loop coming out of the alternator back to flat with the engine. Every branch and weed stem will try to pull it free
Jim
 
Alternators are engineered to be self current limiting. The rating on the model is truly its max current delivery. The magnetism in the stator caused by current fowing
in the stator (generated by the rotating field) is opposed to the magnetism polarity in the rotor. This opposite polarity builds up until the two opposed magnetic
"fields" push each other apart causing an ever smaller increase in total output until it reaches its maximum rated delivery. There is no device in the output that limit
current. and current is not measured by the VR. Generators do not self limit, and will burn up ifm failure to limit current Jim
 
Electricity is a huge mystery to me, but my H did the same thing until I installed a diode from a guy named CharlieU. Very economical, installed quick on my Delco 10SI, I think it regulates voltage somehow or other, I do know that with the diode installed, the amp gage pivots to the "Charge" side immediately on startup and then slowly tapers off, just like it s'posed to do. No need to rev it up. Works just fine. THis used to be his address; Charlie Uthke, Charlie's Repair, 22195 State Hwy 56, Austin, MN? 55912 [email protected]
 
I replaced generators/voltage regulators on 2 IH 140's with 10SI alternators. They are 3 wire with a diode that prevents current backflow through the alternator. This set up allows charging at very low rpms.
 
Ive converted 3 (SH,M,SM) to one wire Delco alternater.Completely stripped all the old harness.Rewired from 'scratch'.Used 14gauge wire for all.I just bought a roll of 14 ga,crinp terms,shrink tube and wrapped it up with black tape.Did the SM over 10 years ago and have ZERO problems.Getting ready to convert another H the same way.
 
Unless I'm really off my bean. In your diagram you need to move your ignition feed to the same
side of the ammeter as your alt feed. Then all will be right with the world. Think about it. Your
ignition is a load. The ammeter cannot register that load if the ammeter is not between it and the
battery. As you stated it will work fine as shown, it just is not correct. In the future if you add lights
you will definitely want them on the same terminal as the alt.; they are a larger load and you will
want that load shown on your ammeter. In stock form when equipped with lights when the engine is stopped and you turn on the lights the ammeter shows a discharge. That will not be possible in the configuration you are showing. If the connections are changed as I suggested when the engine is running the alt charge will push the meter to the
positive charge side of the gauge. Sorry to rain on the parade.
 
Yep, good point. I didn't think carefully about that, having no lights to turn on as a discharge-only. Thanks for your correction and feedback...the ring terminal is easily switched over...now if I could just edit my other post....I'll edit the drawing with the change and post a new photo, delete the original which should get the thread to have the correct info.
 
Yes I am already running 12v. When I have the tractor running and put a voltmeter on my battery I do not get anything above 12v, it should read maybe 13 or so if the charging system was working properly.

Why don't all these posts show up under the topic? I have several replies that have to find individually instead of under the same thread. Re: 1971 Model 140 converting to alternator
 
That looks much better! To avoid added complications in my reply to the other post; one other thing
I that I did not address is the the 30A circuit breaker in the wire to the alternator. What is the
amperage output of the alternator? Most newer alternators have outputs of 60A or more. If at
some point your alternator is putting out near the 60A rating for example your ammeter will show
that the 30A circuit breaker is cycling open-closed due to overload. Under normal conditions for
what you use the tractor for it is most likely fine. If the tractor starts right up with minimal cranking,
and the initial recharge of the battery is low and the alternator can gradually bring the battery
voltage back up to normal without coming anywhere near it full amperage output. But say you
install lights and then for some reason forget them on for an hour now when you start your tractor
the alt will be raising it's output amperage to quickly return the battery to proper voltage. Now your
30A circuit breaker will be getting a pretty good open-close cycle going. The proper thing to do is
to remove that circuit breaker and install a 60A fusible link at the point where your 10awg feed
connects at the starter. If your alternator output is 100 amperes I'm going to say that the 60A link
will still be plenty unless you are using your tractor to jump start a large diesel truck or tractor. So
happy tractoring. One other thing. You should be able to reply to your own thread by clicking the
"reply" within the thread reply box. So unless the forum has an issue you must have clicked "Post
a message" to add the reply that gave the link to the first thread. It just keeps topics more
readable. So please poke that "reply" button and give me a good scolding for my babbling. Lol!
 
http://forums.yesterdaystractors.co...rt=0&sid=97f6527e8dfcd96620234634f2296f21

This is the link to the other part of the thread (!)

On the first page of the other thread is the purported output curve for the mini alternator. I don't think it would ever get much above 2500rpm shaft speed....so...that's why I installed the 30A fuse.

Your comments are well-received however, with a deeper draw or more powerful alternator there would definitely need to be a few changes to the wiring design.
 
There are no pictures shown. This site (to protect young readers) restricts posting photos unless you ask the site moderator )by
requesting permission in the Feedback Form in the blue column to the left. Once granted there is no need to repeat the request.
There are 3 resistors often used in 12v conversion wiring. one is on the light switch to dim the lights (built into the switch),
one is in the ignition circuit to reduce voltage for a 6v coil or a 12v coil that uses a ballast resistor, These two are of about
2.5 ohms and are power dissipation resistors (get hot) and sometimes a 10 ohm resistor in the wire from the #1 spade terminal on a
Delco 10SI to the ignition circuit. before the ballast resistor. This last one acts as a current limiter to prevent the alternator
output from supplying the ignition with voltage that would keep it running when turned off. The use of a small idiot light (Bulb
not led), or a diode will do the same as the resistor. There are diagrams available. Jim
 
There seem to be a lot of "bugs" in this thread, some of the posts won't show in Modern View.

In any case, I would call up Steiner and see what alternator was intended for that bracket. I just made my
own bracket so any fitment issues were clearly the responsibility of me.
 
I do not know what the purpose of a coil relay is. They didn't have one originally.
A failed amp meter will cause no charge, but would also cause a fail to start. The starter would turn, but the ignition gets its voltage from the load side of the amp
meter.
The alternator should be connected the following places.
A 10 gauge wire from the output stud to the load side of the amp meter.
A 14 gauge wire from the #2 terminal to the output stud (6 inches long and if it is a Hitachi, the S terminal).
A 14 gauge wire from the #1 terminal to a light bulb or diode or 10 ohm resistor then from there to the ignition supply after the key.
If different we need to know. Jim
 
(quoted from post at 19:09:03 09/08/17) I do not know what the purpose of a coil relay is. They didn't have one originally.
A failed amp meter will cause no charge, but would also cause a fail to start. The starter would turn, but the ignition gets its voltage from the load side of the amp
meter.
The alternator should be connected the following places.
A 10 gauge wire from the output stud to the load side of the amp meter.
A 14 gauge wire from the #2 terminal to the output stud (6 inches long and if it is a Hitachi, the S terminal).
A 14 gauge wire from the #1 terminal to a light bulb or diode or 10 ohm resistor then from there to the ignition supply after the key.
If different we need to know. Jim

It is a one wire delcotron. I don't have a light bulb wired into this. No key just the original start stop button
 
Anyone else viewing this thread on "Classic View" ? On my end using an iPhone if I click "Modern View" I see far more replies. The original thread topic was started in July and the replies have been sporadic, some showing up in their own threads, just kind of weird.
 
Assuming it is a Delco 10SI, the edge of the rear end plate has a recessed spade terminal socket with 2 spade terminals. One
labeled "1" the other "2". The 1 terminal is connected with 12 ga. wire to the ignition through a diode or marker lamp (bulb not
LED) or 10 ohm 10 watt resistor. It needs to have 12v on that wire to excite the alt, so if a ballast ignition resistor is used in
your tractor, the connection should be on the switch side of the ballast resistor.
The #2 terminal needs to be connected to the output stud on the alt. This is just a short 12ga. 6 inch wire to sense the output
voltage. Jim
 
DO NOT pull the terminals when running. It can ruin components and let smoke out as well as make enough voltage to make shocks
possible!!! Dump the one wire and use a standard three wire as I indicated in this thread. Jim
 
Excuse me by being not electrically savy. When you say dump you mean use the other terminals not go buy a three wire alt?
 
(quoted from post at 07:02:39 09/11/17) Assuming it is a Delco 10SI, the edge of the rear end plate has a recessed spade terminal socket with 2 spade terminals. One
labeled "1" the other "2". The 1 terminal is connected with 12 ga. wire to the ignition through a diode or marker lamp (bulb not
LED) or 10 ohm 10 watt resistor. It needs to have 12v on that wire to excite the alt, so if a ballast ignition resistor is used in
your tractor, the connection should be on the switch side of the ballast resistor.
The #2 terminal needs to be connected to the output stud on the alt. This is just a short 12ga. 6 inch wire to sense the output
voltage. Jim
Again excuse my limited electrical skills

Yes is it a Delco 10SI - it is a one wire, so are those terminals still there?
So my ignition does have resistor right?
mvphoto3316.jpg

Just run a wire from terminal 1 through a diode or marker lamp bulb(like an old turn signal or...??)
Do I run this through the dash at all or cut it under the gas tank somewhere?
And number 2 terminal to the output stud on alternator.
I hate to repeat what you posted but I need to make sure, got to get this up and get some bush hogging done.
 
On a Delco 10SI internal regulated alternator, #2 pin is for sensing charge level of the battery. On a tractor it is often connected to alternator output.

#1 pin is to excite or jump start the alternator. A momentary voltage is applied to start charging and then trio diode supplies power to the regulator as long as engine continues to run.

The purpose of a resistor, diode, or lamp between #1 pin and output of ignition switch is two-fold. (1)Without it the diode trio can back feed the circuit to the ignition coil causing the engine to keep running when switch is turned off. and (2) As indicated, if there is a high resistance or failure in the alternator output to battery wire it will prevent an alternate charge path from diode trio that could overload and wipe out that trio.
 
If you have an amp gauge,you don't need a 'warning light'.You don't need one even if you don't have a gauge
 
You can attach one if you like. It needs to be ungrounded, and the wire from the #1 Delco terminal passes through it on the way to
the ignition voltage at the ignition switch. Several 12v indicator lights are available with a plastic case and two connections.
Do not use an LED lamp. If you use the light do not use a diode or resistor in that circuit. Jim
 
Something like shown in the link would be fine. Mount in little sheet metal with a hole made with a hole saw. Bend a 90 degree lip on top over the bulb to make a drip cover. There are amber bulbs available to make it more of a warning lamp.
Lamp socket
 
(quoted from post at 10:24:47 09/17/17) Something like shown in the link would be fine. Mount in little sheet metal with a hole made with a hole saw. Bend a 90 degree lip on top over the bulb to make a drip cover. There are amber bulbs available to make it more of a warning lamp.
Lamp socket

Thanks. Saw those but was concerned about blowing them if the got wet. Was looking for something enclosed. But I think I will go with one of these
 
Does it show charge on the amp gauge? If so,dont worry. just get rid of the 'idiot light' and run it.
 
Bulb may have to much resistance to it and if it does you get a no charge problem. I would try taking it out of the circuit and see if the alternator then charges and if it does can you shut the engine off with the switch?? My self I prefer the diode method but they seem to be harder to come by now days since Radio shake went out of business.
 
(quoted from post at 11:28:12 09/26/17) Bulb may have to much resistance to it and if it does you get a no charge problem. I would try taking it out of the circuit and see if the alternator then charges and if it does can you shut the engine off with the switch?? My self I prefer the diode method but they seem to be harder to come by now days since Radio shake went out of business.

So by taking it out of the circuit you mean just wire directly from terminal one to the on off switch?
 
(quoted from post at 11:23:41 09/26/17) Does it show charge on the amp gauge? If so,dont worry. just get rid of the 'idiot light' and run it.

Not too confident that the amp gauge works. I check resistance in it and also jumpers to an AA battery. The needle moved a bit but did not come close to pegging out.
 
I don't understand the need for a light or 'diode'. I have 5 old tractors with alternators.All there is an amp meter between the alt and battery.They all charge as should,tractor shuts off as should,and no 'bleeding' over time. Someone please explain. Thanks.Steve
 
Your just lucky then. On the common Delco 10SI it is common for the excite circuit to back feed the ignition system and when it does that you cannot shut the engine down by way of the ignition switch. I have tried it many ways an never had one that did not back feed if I did not use a light bulb which I do not like or a diode or a simple low ohm ballast resister
 
From the #1 terminal on the alternator edge (spade terminal) a 14 gauge wire (or 12, no issue) goes to the bulb connection. From the other bulb connection a 14ga wire goes to the
ignition switch where it connects to power the coil and or the resistor. THe #2 spade connector goes to the out put stud on the alternator, (short 6" 14Ga wire) What you
described is incorrect. Jim
 
Some rebuitl and imported alternators will self excite with no real problem if turned at enough RPM. If purchased as a one wire system the regulator is not stock, and is internally connected to the battery source to self excite at lower RPM (sometimes low enough to use on tractors at idle) A Standard 10SI should have a wire from #2 to the output stud to control voltage more accurately. Jim
 
A light or diode is used only with a 3 wire alternator. Not needed on One wire configuration.

On a 3 wire, the #1 pin supplies a jump start to the alternator and #2 is connected to a battery source to tell the alternator the charge level of the battery. This is incorporated internally in a one wire configuration.

Once started up, a diode trio in the alternator supplies operating current to the regulator at the point where pin #1 connects.

When the switch is turned off, battery power path through the switch to the ignition is turned off and the engine should shut down. However, the diode trio may continue to power the regulator and this current can flow back through pin 1 to the switch and then to the coil allowing the engine to continue to run.

A diode is a one way device. When placed between switch and #1 pin it allows current to flow to start the alternator, but when switch is turned off it blocks the back flow from the alternator allowing the engine to shut down.

A lamp in the line limits the current to a low level sufficient to jump start the alternator, but not high enough to allow return current to power the ignition allowing the engine to shut down.
 
This thread is so garbled up now, I cant really understand whats what. You should really start another one instead of replying over and over to this one. Are you still using the 1 wire alt?
 
"Any idea why the light would stay on? "

Is the battery connected neg to ground ? Your other wiring sounds correct, #1 connected to switched power through the alt light,#2 connected to the BAT stud. A $3 delco alt harness repair plug from the auto parts store will be a lot more professional looking and much safer than those taped up connectors hanging off the alternator. If that #2 sense wire moves 1/8 inch and shorts against the alt case, I guarantee you will have an electrical fire.
 
(quoted from post at 13:57:21 09/26/17) From the #1 terminal on the alternator edge (spade terminal) a 14 gauge wire (or 12, no issue) goes to the bulb connection. From the other bulb connection a 14ga wire goes to the
ignition switch where it connects to power the coil and or the resistor. THe #2 spade connector goes to the out put stud on the alternator, (short 6" 14Ga wire) What you
described is incorrect. Jim

I am using 10ga wire all around, do you suppose too much resistance?
 
"the light is staying on"

There's only one explanation which makes sense to me...that there's a potential difference across the lamp.

Two possibilities come to mind. First somehow the 14.x voltage of the alternator isn't reaching the ignition switch terminal. Or second, that the B+ wire between the alternator and battery (and likely thru the ammeter) isn't a good conductor pathway.

I would use a voltmeter and try to measure the voltage from each side of the light bulb to ground. And you could also measure from one bulb terminal to the other, to see the potential difference (voltage drop) across the bulb. Another good measurement to take is from the B+ battery terminal to the B- battery terminal, when you think the alternator is charging. If its 12.x then its probably not charging. If its 14.x then its charging. You could also vary the electrical load by turning on and off the main headlights and see the variation in the B+/B- voltage again to assess charging under a load more than just the ignition.
 

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