MF135 Alternator question

I'm adding some lighting to my 1972 diesel MF 135 that didn't come with it (turn signals, hazard flashers, and some off road lighting), and I have a question about the alternator.

A little background: my machine may have had a conversion from a generator to an alternator at some time, but I'm not positive about that. The wiring seems to correspond pretty well to an OEM MF drawing of an electrical system for a diesel WITH AN ALTERNATOR that I have. Also has a newer 4 post voltage regulator, not the 3 post kind that would have been installed with a generator. It runs great, is starting very well, even under the sub-zero conditions we've got here now. Some of the wiring has been up-graded somewhat (newer connectors at some locations, fuses added where they should be but not OEM, and all connections recently cleaned up too).


This puppy has what I think is a Delco-Remy 10DN alternator(exterior voltage regulator required) and for all I can tell, it looks to be much newer than what a '72 MF135 probably came with. By the ammeter, and everything else I can see, it seems to be working just fine. I have researched and investigated these alternators some and understand that the lowest output for the 10DN is somewhere around 37 Amps with the next higher output available to be somewhere around 60 Amps in the next unit up the chain. My alternator question here: How can a feller check the output of the currently working alternator to know exactly what it's real output is? Is there a certain RPM to take a measurement at?

I have taken this thing off the MF135 and searched for some identifying numbers, and can find none except a few on one of the buttons on the hookup end, and I can find no reference to these exact numbers anywhere, and neither can several of the local parts people I deal with.

If I have the +/- 60 amp model, I probably don't need to buy one, but if I have the lower rated output, I might need to upgrade just to be safe with the new equipment.

A secondary question here (maybe call it a kicker): I down loaded the current Delcoremy Electrical Specifications and Selection Guide to investigate my mystery "alternator" and found a page that refers to the 10DN as "10DN Generator" and what this Guide shows seems to look almost identical to what I have...picture only shows a side view drawing. Could I have a "generator" instead of an alternator? Or has the terminology just changed or what? I have found many other pictures and references on the web that show this exact piece of equipment and they have all called it an "alternator" (I could post a picture if that would help). What gives? Thankin' you in advance for any comments you might have time to offer, Yerz, The Frontranger
 
(quoted from post at 00:53:00 12/11/09) I'm adding some lighting to my 1972 diesel MF 135 that didn't come with it (turn signals, hazard flashers, and some off road lighting), and I have a question about the alternator.

A little background: my machine may have had a conversion from a generator to an alternator at some time, but I'm not positive about that. The wiring seems to correspond pretty well to an OEM MF drawing of an electrical system for a diesel WITH AN ALTERNATOR that I have. Also has a newer 4 post voltage regulator, not the 3 post kind that would have been installed with a generator. It runs great, is starting very well, even under the sub-zero conditions we've got here now. Some of the wiring has been up-graded somewhat (newer connectors at some locations, fuses added where they should be but not OEM, and all connections recently cleaned up too).


This puppy has what I think is a Delco-Remy 10DN alternator(exterior voltage regulator required) and for all I can tell, it looks to be much newer than what a '72 MF135 probably came with. By the ammeter, and everything else I can see, it seems to be working just fine. I have researched and investigated these alternators some and understand that the lowest output for the 10DN is somewhere around 37 Amps with the next higher output available to be somewhere around 60 Amps in the next unit up the chain. My alternator question here: How can a feller check the output of the currently working alternator to know exactly what it's real output is? Is there a certain RPM to take a measurement at?

I have taken this thing off the MF135 and searched for some identifying numbers, and can find none except a few on one of the buttons on the hookup end, and I can find no reference to these exact numbers anywhere, and neither can several of the local parts people I deal with.

If I have the +/- 60 amp model, I probably don't need to buy one, but if I have the lower rated output, I might need to upgrade just to be safe with the new equipment.

A secondary question here (maybe call it a kicker): I down loaded the current Delcoremy Electrical Specifications and Selection Guide to investigate my mystery "alternator" and found a page that refers to the 10DN as "10DN Generator" and what this Guide shows seems to look almost identical to what I have...picture only shows a side view drawing. Could I have a "generator" instead of an alternator? Or has the terminology just changed or what? I have found many other pictures and references on the web that show this exact piece of equipment and they have all called it an "alternator" (I could post a picture if that would help). What gives? Thankin' you in advance for any comments you might have time to offer, Yerz, The Frontranger

If it is a 10DN, it is an alternator with separate regulator. I very seriously doubt that you need any kind of upgrade, as even the least output versions of these far exceed the OEM generator.
alt_Delcotron_10DN.jpg

Actually, as I typed, I lost sight of the model.......what you have may be OEM.
 
I agree, just add your lights. If they're super high power and your alternator can't keep up, then you could look at a bigger one. I doubt you'll need any more than 37 amps unless you're running a dozen lights. Dave
 
Thanks for the comments. JMOR's pic is what I've got now exactly, and for what it's worth, my Service manual does show a diesel engine WITH a generator, and it is a completely different piece of equipment. I do appreciate your(alls) thinking about how to approach this. At most, I might be running the driving lights, and the flashers, and maybe the panel lights all at once, and I would hope that would not be exceeding the 37 Amps too.

I am curious about how one would measure the actual output of the alternator say at idle and at operating RPM's...would that take one of those clamp-around-the-wire voltage meters? Might just be usefulinformation to know.

Will press on from here, Thanks again! Yerz, The Frontranger
P.S. Hope you enjoy this pic from my place last summer! You can see the mountains as they actually look from my place in the background.
a7749.jpg
 
For some reason unknown to me, Delco called them "generators" in the early days of alternators.

To check the max output of the alt, disconnect the 2 wire plug on the back of the alt. and jumper from the bat post to the F terminal. Watch the ammeter as you run the engine up to fast idle.
 
(quoted from post at 09:41:17 12/11/09) For some reason unknown to me, Delco called them "generators" in the early days of alternators.

To check the max output of the alt, disconnect the 2 wire plug on the back of the alt. and jumper from the bat post to the F terminal. Watch the ammeter as you run the engine up to fast idle.
es, Frontranger, what TracrormanNC advises will yield the maximum output current that your 10DN will pump into your battery in its present state of charge.....
That current level will depend on your battery's state of charge, being greater into a nearly dead battery than into a fully charged battery. It will not be a test of the alternators maximum output capability. To do a maximum output test, you need a high power adjustable resistive load, voltmeter, ammeter.
 
Yes, the clamp around DC ammeters would be the handiest. But the dash ammeter will tell you almost as much.

With lights off after a start, if the alternator wiring is sturdy enough to the ammeter and the battery, right after a start is when the battery will take the most amps. With lights off the battery gets it all and you can get an fair idea of the alternator capacity then. If the voltage regulator is holding voltage right, the current will taper smoothly with time as the battery comes up to full charge.

If you turn the lights on right after starting and the ammeter still shows a little charge, you have enough alternator, though you may have to run longer to get the battery charged up with the lights on.

An automotive electric shop can change the stator in the Delco case to get a higher current rating.

If you make the wire from the alternator to the ammeter bigger than it is you will get more current from the alternator.

Gerald J.
 

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