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anyone added an alternator?

2683 Views 11 Replies 8 Participants Last post by  NSBolens
I have a Bolens tubeframe that has been re-powered with a 13hp honda clone. I intend to use a small atv winch to lift and lower a snowplow, and I'm concerned about the charging system being able to keep up demand, I have 2 amber marker lights on the front, 2 Red on the back, and they are wired to a flasher. I also have 2 55w halogen driving lights on the front. the charging circuit on my motor puts out 3 amps, which is pretty much absorbed by all of my lights.

I'm considering adding a vehicle alternator to run off an accessory belt, a spare groove on the engine pulley. I have in mind a 75 amp ford alternator from a little ranger.

Has anyone done this? Does anyone have any ideas or constructive criticism?
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I've done it on farm tractors but it's been awhile,I believe I used an older GM alternator and I remember there was something about it that I only needed to hook up one wire to it to charge the battery but I don't remember the details.A friend of mine that rebuilds starters and alternators suggested it and I just did it like he said and it worked fine.It was on a David Brown tractor with a Lucas electrical system,when the generator went bad,that's how we fixed it.:thThumbsU
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You want an alternator with an internal regulator. I used a delco (gm) on my 10 hp that I put in an old Alis Chalmers.
The big post on the alt shell goes to the battery and one of the plug- in style connector wires go to ign (not sure which one- one goes to ign and one to an idiot light, we don't need the idiot light one.)
For our application, direction of rotation doesn't matter (the cooling blades are the only directional things on the unit and we are out in the open air anyway- not under a hot hood).
On the GMs the old "V" belt pulleys have the same inner bore as the serpentine pulleys, so you can swap pulleys (use an impact gun on the nut) to use a newer style alternator and still use a v-belt, the plug in is a different style but have the same function.
I had a 105 amp rebuilt alternator leftover from a project and swapped pulleys and put it on the Alis. Works fine. It does need to be spun with a pulley more than just a couple inches in diameter to get it to put out current. I used a 4" (I think).
I use a couple of aux lights in front and one in back- when you turn them on, the motor idles down a little bit. All the power you use will come from the alternator - not the battery (unless the engine is off or idling). This is why guys burn up their alternators with big off road winching sometimes.
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Check this link out for everything you wanted to know abt using GM 1 and 3 wire alternators. I would suggest the 3 wire as it is just as easy to wire if you follow along with this sites recommendations.

Page 2 of the article is the good stuff
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The wiring diagram is available on as well--its easy to hok up a GM altenator though,you just run a 12V hot wire from the ignition,hot only when the key is "on",to the #1 terminal,and you put a #194 marker lamp bulb in line to that terminal,and you just jump the #2 terminal to the stud on the rear of the altenator (the main output) and its done..the rest is just fabbing up a suitable mounting bracket..I find one off an old 250 straight six is easily adaptable to most inline tractor engines and small HP engines..
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If you use a GM one wire alternator,,, the wire connection "must" be very good,,, as that alternator uses an internal regulator.
A lot of tractor guys will also use Nissan and toyota 1 wire alternators as well. they are very small and very reliable.

I have a Ford 75 amp alternator on hand, it's internally regulated, of the 3 wire variety. I think I'm going to give that a try. thanks for all the responses.
How do you suspend the alternator on the tractor?
well i'm thinkg of putting mine in one of two possible locations. I could have it hang out the side like a hydraulic pump, or it could probably squeeze under the motor with the pulley facing backwards, and a belt going straight down. another thought i had since i have a mid pto and don't use it, was to put it on that. when i use my snowcaster, I charge the battery - winch draining the battery? fire up the pto. I'll probably end up putting it under the motor, seems the neatest and easiest.
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You'll have to fab up your own brackets,usually the stock ones used on the vehicle it came from can be modified to work,without much difficulty.. I said earlier,the straight six chevy engine altenator brackets are easy to adapt to most inline engines and small engines,and they are still fairly common in junkyards,if you use an older GM altenator....
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I can fab up brackets no problem, and I'm going to use this ford 75 amp alternator, as I already have it and don't have a use for it. It also has a fairly small case, so it should be able to squeeze into where i want it to go.
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