Max IV external alternator install

[xbunsenx]

After I added a 22" LED lightbar, my internal alternator could not keep up with the demand, so I decided to add an external alternator.

Items Used
Kohler Front Drive Shaft: 24-144-23S http://www.smallenginewarehouse.com/KO-2414423S-D1.html
4.5" Engine Pulley: https://phoenix-mfg.com/V-Groove-Dri...el_p_1551.html https://www.amazon.com/Phoenix-V-Bel...5956893&sr=8-3
10SI Alternator: https://shop.advanceautoparts.com/p/...hTerm=7127-3av
Alternator Pigtail: https://shop.advanceautoparts.com/p/...5841/5472830-p
Belt: Dayco 26" #L426 https://shop.advanceautoparts.com/p/...earchTerm=l426

Installed front drive shaft with 4 metric bolts (don't know size)


Fabricating a custom bracket using old alternator as a guide


Bracket test fit


Testing operation with new alternator


Painted bracket (shiny black)


Installation completed (Yes, that is a car horn)


Once I installed the bracket and alternator, I connected the #1 terminal to the ignition wire found at the engine. My 2000 Max IV used a yellow wire in the harness. The #2 wire was connected to the alternator BAT terminal. The BAT terminal was connected to the positive battery terminal using a lawnmower battery cable.


During testing I noticed that upon initial startup, the alternator is not spinning fast enough to excite. Once the engine is revved up once, it charges at idle. It's producing 14 volts. The internal alternator was not operating during testing of the external alternator. I decided to use a GM alternator because it is readily available almost anywhere. I might get a larger drive pulley down the road.

**UPDATE**
Based on feedback from the community, I disabled the internal alternator by disconnecting the voltage regulator. I also did more testing and found that the external alternator does indeed charge at initial startup without revving the engine to excite. I don't have an explanation for why it did not before, but it does now. I will leave the 4.5" drive pulley in place. The alternator puts out 14.7v at idle.

[thejunkman]

Nice job

[dirtdobber]

Looks good.

[Chiefdiesel]

That bracket is nice! I have a GM Delco 1 wire 35 amp alt on my MaxlV. I started with a 4 1/2 stub shaft aluminum pulley. That setup excited at ~3000 rpm. The current pulley is 8 7/8 (closer to the "ideal" 3:1 ratio), it excites @~1800 rpm... downside is this large pulley is cast iron=heavy! Once the alternator is excited, they continue to charge at any rpm until the has stopped. FYI, I needed to "bump up" the idle when the alternator did kick on. I think about the 14hp Vangard engines in some Argos with the external alternator option...power loss.

[xbunsenx]

Thank you all for the compliments. I have driven it around and not noticed any power loss yet. I wanted to keep the engine pulley smaller to reduce load and still get charge. What I didn't think of when I was calculating the alternator RPM at idle was that the belt sits down into the engine pulley which decreased the effective diameter. The internal alternator is charging at idle so I am not terribly concerned. Overall I am real happy with how the project went and was looking forward to showing it off this weekend at Busco and running my LED lightbar all night long with no dead battery. I need to add more lights now to justify this huge alternator.

[Chiefdiesel]

I have a box of misc. hardware from various projects over the years. If the larger pulley was made of a lighter material it would be awesome. Actually, when moving you don't feel a power loss, but weighting 2.5lbs more, you know its having an effect. Are you going to disable the oem charging system?

[xbunsenx]

From my limited research, I have found that you should be able to run both without consequence. As long as both alternators are producing the same voltage, they will be fine running in tandem. There are car stereo enthusiasts that run dual alternators for their massive power requirements. they are run in parallel.

[ARGOJIM]

That is a nice looking set up.

Tommy the Argo does not feel a power loss as far as I can tell, they use the Denso mini alternator at either 30,40 or 60 amp with roughly a 4" drive pulley , they exite at near idle so once the machine starts its charging

[Chiefdiesel]

20200321_174717.jpg20200404_125318.jpg

My set up

[xbunsenx]

Jim,

Do you know if Argo disables the internal alternator when they add the external option?