Put an Alternator on my GR2120

WI_Hedgehog

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BX2370 (impliment details in Profile-About)
Apr 24, 2024
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Milwaukee, Wisconsin, U.S.A.
Finally found the spec.... yeesh stuff like this should be easier to find.

14 amps for the OEM dynamo. which makes sense when you eyeball the size of the 2 blue wires....

Can't believe the Aux skt is fused for 30 amps, will try to find the wiring diagram for that curiosity !


15 amp rect/reg units do NOT like to be 'maxxed out' . Normal operating for
OK, found a GR2100 'series' WSM
points of interest
1) main fuse slow blow 40 amp
2) NO fuse between regulator and battery
3) IG/M is 10 amp fuse ( so operating current < 10 amps )
4) replacement dynamo about $120
5) replacement regulator about $50
That makes sense given the tiny wire size and how small the electron pump is. Aux lighting on the BX is:
+ 10A fused/switched
+ 20A fused/constant
- return wire (one) that looked to be the same size as the other two.

I guess I'll have to monitor the current draw of the lightning I'm adding before adding heated clothing, and maybe replace the 14A electron pumper next year with a 35A unit.
 
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Hkb82

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M7060, Ford 5600, can-am defender
Nov 17, 2021
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Hey maybe take your own advice and cruise on by. 🤣
My advise was Maybe it’s time you shop for another colour tractor if the oem parts are under preforming and junk.
If I believed this I would take my own advise but I don’t. You didn’t offend me at all so don’t worry about it.
But if you ask? Might get a an answer you might not agree with.
Or you might get another member replying with a useless response or comparison discouraging new members from posting or joining in.
unfortunately some times peoples personality do show in a post or forum.
 

Oleracer

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B2150 Kubota LA 350 750 Woods S250 Bobcat 300x deere
Jul 18, 2024
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My advise was Maybe it’s time you shop for another colour tractor if the oem parts are under preforming and junk.
If I believed this I would take my own advise but I don’t. You didn’t offend me at all so don’t worry about it.

Or you might get another member replying with a useless response or comparison discouraging new members from posting or joining in.
unfortunately some times peoples personality do show in a post or forum.
Sorry wont bite.
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
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When you do upgrade the charging circuit, be sure to upgrade the wiring and add a fuse from the alternator . Local car show, guy had 120 amp shiny chrome alternator yet still has OEM wiring. He didn't like what I said about his pisspoor useless upgrade.
 
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WI_Hedgehog

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BX2370 (impliment details in Profile-About)
Apr 24, 2024
360
378
63
Milwaukee, Wisconsin, U.S.A.
When you do upgrade the charging circuit, be sure to upgrade the wiring and add a fuse from the alternator . Local car show, guy had 120 amp shiny chrome alternator yet still has OEM wiring. He didn't like what I said about his pisspoor useless upgrade.
I can't see the existing OEM wire off my alternator handing a 40A slow-blow circuit, 30A surge looked like it might be a lot, 20A continuous I could see (though I do need glasses), and having a 14A pump??? Kind of crazy, but the Japanese do know their stuff...usually (alternators often seem a bit undersized to me).

If my alternator gets replaced I'll put in a second fuse block, the first looks difficult to access. I twice looked at adding fuses in the spare openings, finding the rear aux. lighting wires seemed a much better idea.
 

GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,652
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Greensville,Ontario,Canada
To carry 40 amps, you need 8 gauge wire, which is a bit bigger than 1/8th inch in diameter. That's the copper conductor NOT the insulation. While #8 is fine for short diatsances, you'll need to go biiger ( smaller # ) for long runs to reduce IIR losses and voltage drops.
The current Canadian Kubota price for the BX23S alternator is $650. Seems it's rated for 45 amps, so a LOT of power in a very small package.
Unlikely I can get a CS-130 to physically fit in, but I'd try, to save $750 !!!
 
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WI_Hedgehog

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BX2370 (impliment details in Profile-About)
Apr 24, 2024
360
378
63
Milwaukee, Wisconsin, U.S.A.
That's the thing, my BX doesn't have that tiny dynamo, it has a tiny alternator, so maybe it's more than 14A.

14 gauge wire (which is what the OEM wire "looks like" to me) will carry 35A short-distances (under 6 feet), though it will have a voltage drop and warm up. Should 6 AWG be used for 40A? Ideally, like for a starter.

Here's a comprehensive online wire size calculator:

For my add-on lighting circuit I should figure:
14V source
2V drop
Copper
8A maximum current draw
10 feet
120°F maximum wire temperature
=12AWG (which the OEM feed is clearly not, it looks like 16AWG fused at 20A)

And here's where real-world experience comes in. If I split 10 lights drawing 8A total into left and right light bars each bar draws about 1/2 the total current, and if the multi-wire cable I'm using to control banks of lights has two return wires that's 1/2 current again resulting in 2A per return wire, and according to the calculator that requires two 18 AWG wires. Since it's for myself and not someone else I'm running bundled cable with 22 AWG wires suggesting a 6V drop, but in reality it works fine. Why?

The source voltage from the tractor is 14V with the engine running, not 12V, and LED lights will run at 11V just fine due to having regulator circuits inside them, so that's a 3V allowable drop end-to-end, which in reality is more like 8' total length. Allowing for a 170°F wire temperature given the lights will be run for snow plowing and the starting temperature is not 70°F (it's more like 25°F or less) meaning there's less heat which causes less resistance and less power needed, 22AWG x2 per light bar is just fine.

But I will look at the alternator this weekend.
 
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GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,652
5,041
113
Greensville,Ontario,Canada
Did you actually measure the current of the LEDs or just go by 'what's on the box' ??
A 3 volt drop is unacceptable ! Basic electrical math.... 3 volts x 2 amps = 6 WATTS of wasted power. That's if the LEDs are drawing 2 amps...hence my query ,have you measured the current.

Also you have to measure the wire not just look at it. 18 and 20 look the same to me, 16 and 18 the same.

? 22 x 2... is that 2, 22ga wires in parallel of a single feed and a ground ? 2 x 22 (twisted together) makes about a 20ga conductor.

BTW, the BX2370 and BX23S have same 45 amp alternator, just checked.
 

John T

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2017 BX23S
May 5, 2017
863
343
63
under a rock
This is not a just a lawnmower. Show me any other Lawnmower with a 3 cyl. water cooled diesel engine on it.
Xmark along with others offer and (offered) diesels.

Generally they are not popular with commercial Lawn Goomers ....
they are heavy sluggish pigs compared to the Gas jobs.

I think Grasshopper actually offered a 3cyl Kubota engine.... 27 hp.
 

WI_Hedgehog

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BX2370 (impliment details in Profile-About)
Apr 24, 2024
360
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Milwaukee, Wisconsin, U.S.A.
Did you actually measure the current of the LEDs or just go by 'what's on the box' ??
A 3 volt drop is unacceptable ! Basic electrical math.... 3 volts x 2 amps = 6 WATTS of wasted power. That's if the LEDs are drawing 2 amps...hence my query ,have you measured the current.

Also you have to measure the wire not just look at it. 18 and 20 look the same to me, 16 and 18 the same.

? 22 x 2... is that 2, 22ga wires in parallel of a single feed and a ground ? 2 x 22 (twisted together) makes about a 20ga conductor.

BTW, the BX2370 and BX23S have same 45 amp alternator, just checked.
Other forum members were pretty excited about NiLight (kind of like "nightlight" with a bunch of letters missing) so I bought that brand because for the job they were extremely affordable, though they definitely have shortcomings. The mfg claims 18W, and knowing they come from China where lying is illegal but "everyone exaggerates in marketing claims" (meaning exaggerating by less than 50% is legal, 50% or more technically illegal) I hooked them up up one-by-one in the shop to a lithium automotive battery and each drew around 0.8A, which at 13.2V = 10.56W, noting some of that power is used by driver circuit and "lumens" would be a better way to measure the light output. Regardless, they seem to be pretty uniform in the color output spectrum and a good value.

If the OEM alternator puts out 14.2V, (10) lights will draw:
10.56W each / 14.2V x 10 lights = 7.43A + beacon = 8A (when they're all on)

LED's forward threshold voltage has to be overcome, then they conduct as much current as they can which is why a driver circuit is needed, so once you fire them off the voltage "isn't that important" as they're current-driven devices.

For reference, filament bulbs have a resistive wire and therefore voltage is needed to overcome that resistance, and older vehicles idled up or down the headlights would change brightness; similarly in flashlights as the batteries wore down the light was less bright. LED headlights and flashlights aren't like that, they are the same brightness until the cells cannot put out the required current, then they dim for a number of seconds (not minutes) then turn off.

So, as long as enough current is available to drive the LEDs and there's enough voltage to overcome resistance and keep the circuits operating, we're good! If I had to guess I'd think about 8V is where that cutoff might lie, but that is circuit dependent; I don't want to risk ruining a LED circuit which likely has few if any safety features because there's no real up-side in that, so I won't be pulling out a variable resistor to test what voltage that actually is. If this whole thing lets the smoke out on me I'll post pictures, but I think it will work.

There are 22AWG x 4 pair (stranded insulated) in the cable, which is 6 wires for lights, 2 for return:
#1: Front Spot
#2: Front Flood
#3: Right-Side Flood (2 lights)
#4: "Your other right!"-Side Flood (2 lights)
#5: Rear Flood
#6: Beacon
#7 & #8: Neutral return.

Okay, technically there are two flood lights for each side, so 2-right and 2-left = 4, so one (+) wire on each side could power that side's 2 side-lights. However after looking at more fall-harvest-at-night videos I may really want 4 front flood lights instead of two...anyway, running six power wires to the left light bar and six power wires to the right light bar means at the main switch box I now have options on what switch turns on what lights. (I spend way too much time on design...)

---
Of course you're right about wire insulation making it hard to determine wire gauge; I know the BX alternator wire isn't 12AWG because the diameter simply isn't large enough, but what is it really? I can only guess from trying to remember what I saw when I looked at it. Let's hope it's enough--maybe I should check, but likely I'll just feel how warm the wire in the rear aux. lighting harness is and call that a reasonable test.
 

Oleracer

Well-known member

Equipment
B2150 Kubota LA 350 750 Woods S250 Bobcat 300x deere
Jul 18, 2024
224
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63
CT
To carry 40 amps, you need 8 gauge wire, which is a bit bigger than 1/8th inch in diameter. That's the copper conductor NOT the insulation. While #8 is fine for short diatsances, you'll need to go biiger ( smaller # ) for long runs to reduce IIR losses and voltage drops.
The current Canadian Kubota price for the BX23S alternator is $650. Seems it's rated for 45 amps, so a LOT of power in a very small package.
Unlikely I can get a CS-130 to physically fit in, but I'd try, to save $750 !!!
Just a note. CS130 can be had at 35-55-75 and 125 amp. Probably 165 if you want too pay but way under 200 bucks. Simple wiring and lower amps available almost anywhere. Easily clocked for to fit about anyplace its needed. But i dont work on the small BX series so it would be interesting to see.
 
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GreensvilleJay

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BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,652
5,041
113
Greensville,Ontario,Canada
Yes, LED 'power ratings' are interesting...
The ones you mention are rated for 24 volts, so when connected to a 24 volt battery, drawing 800ma, you 'magically' get the '18W' rating they post. While most use 12 volt batteries , some do use 24 volts ( old jeeps, lots of off road equipment). If you want them to be brighter, boost the 12v battery to 24 Volts, cost $5.
Yes, LEDs are constant current devices ,used 1000s of them in Teletype current loops a long ,long time ago.
All 5 of my CS130 equipped tractors were 35 amp units. Freebies pulled from Cavaliers, decades ago. I had no need of more amps back then.

Kinda wished I'd kept a Teletype ASR-33 though......
 
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