Alternator question

grandpa Love

Well-known Member
My wife's 640 has a 3 wire alternator and my 960 has a 1 wire. Mine no longer charges,time for a new one. I have seen posts on here that the one wire doesn't start charging until tractor hits a certain RPM. Also read where some folks don't like them, saying it's hard on motor to rev up cold. So , question is, do you have to rev motor as soon as you crank it to make alt start charging,or will it start at any point that the RPM's are right? Thanks. Kevin in Central AL.
 
Yeah, I don't know why people think you have to rev up a cold engine. Generally, if there is enough juice in the battery to turn it over to start it there's enough to run it for a half hour, much less a few minutes till it warms up a bit.
The only reason i can see for revving it right away is maybe you'll forget to do it later.
 
How many RPM's does it take to start one charging? I thought that may be issue on mine but ran it up to full throttle and still didn't show charging. Been like that for a couple months. Been hooking charger up as needed.
 
I recently read an article on this at Pirate4x4.com. He says that it is ironic that one wire alternators are best suited for vehicles like tractors, but may they not generate enough alternator rpms to self excite the alternator.

This contradicts articles that say that one wire alternators excite at lower rpms than say a normal GM 10si. It may be the Pirate 4x4 author did not include the special voltage regulator which excites at a lower rpm than a normal voltage regulator. I think these may be the same regulators used in marine applications. So it really depends on whether your one wire is that kind of alternator. You would have to look at the IC regulator and determine the part number.
 
I forgot to add that there are numerous posts and discussions concerning this and I am going to try to read as many as I can.
 

What do folks do start there tractor up and idle around all day... Its not a issue and never was... Use the correct pulley and belt life will be good...
 
Here's my experience, I have an naa with a 3 wire alternator, needs to be brought just above an idle to show charge on the volunteer occasionally, often charges right at idle tho. I have had a ford 650, 3400,8000,3910, John Deere 210C, Daewoo excavator, Peugeot moped and the neighbors Ford naa all have been fitted with single wire alternators and never noticed one not charging as soon as I started it. So if there is a problem with one wire alternators I think it's few and far between or else modern ones have greatly improved. I wouldn't hesitate to use one at all.
 
I don't think it is a real life issue , just use it as you normally would .

Maybe if you are one of the few who have an N series that actually idles under 500 rpm and you are trying to make it fail by letting it idle for 40 hours until the battery goes dead ......

If your alternator needs to spin at 1000 - 1200 rpm and your alternator pulley is half the diameter of the crank pulley then 500 - 600 rpm is very close .

Now if someone wants to get technical I am sure they can cite laboratory test results and kick this football all over the field . IE , if you want to know how to build a watch then it is an interesting topic , If you just want to know what time it is you are good to go .
 
I am not a fan of one wires the 3 wires are cheaper and work better. I bought a 340 IHC with a one wire it takes 1800 rpm to get it to start charging.
 
(quoted from post at 11:01:17 11/05/17) I am not a fan of one wires the 3 wires are cheaper and work better. I bought a 340 IHC with a one wire it takes 1800 rpm to get it to start charging.

I am a big fan of the "Idiot Light" , If it goes out you go on your way . If you leave the key on a red light reminds you to turn it off . A few times I have pulled the diesel fuel shut off and forgot the key switch . Lucky for me there were no points to burn up but I had to jump start it just the same .

I had an 8N with a loose belt . I did not hear it squealing but I did notice the red dash light flickering . An amp meter would have just smiled at me and said nothing :)
 
Depending how it's geared it shouldn't take more than a little to start charging, but if full rpm isn't charging then yes your alternator is dead
 
When you start your tractor the alternator will start charging unless your belt is loose or it is going bad. The 1 wire is easier to hook up but they are more expensive if you have to rebuild it. If you look on ebay you will see the difference in prices for the 1 wire versus 3 wire delco alternators. just my 3 cents worth.
 

Whut dumarse lets his N sit there and idle under 500 RPM. The base low RPM is used to adjust the carb after that idle it UP :D

A thousand are 1500 RPM is not gonna hurt it Damm folks need to get a life....
 

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