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2nd 12v alternator on nhc 250

my blood flows OD

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I was just thinking about making a bracket to run a 2nd altinator on my m-813. This was I can run a completely separate 12v system with its own battery under the hood and its own fuse panel.
it should be really simple. Just didn't know if anyone has done this before and had any insight on fabricating the bracket and routing the belts or maybe a sheeve pulley that maybe available.

thanks guys, any and all advice is greatly appreciated.
 

goldneagle

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Cool any advice would be great. I have decent fab skills so it shout be to bad.
If you are not planning to install A/C on your truck you can purchase the A/C compressor bracket and use it for the alternator. It goes under the power steering pump. It cost me $230 which came with all the bolts and even the proper fan belts.
 

Postman515

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The 915 Series and HMMWV run these alternators as there upgrade. 12v for lights etc. 24v for starting. Guessing it wouldn't take much to make it work but haven't personally done one. These I have come with External regulator too. There listed in the classifieds.
IMG_3325.jpg
 

my blood flows OD

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That's might be an option. I wonder if anyone has looked at the 14L and the 8.3L side by side and looked at what it would take to do this.
I think the route I more likely gonna take is to keep my stock 24v system unaltered and add a 2nd altinator like a GM (ac Delco) with an internal voltage regulator. And just do the old GM one wire trick to it
 

Postman515

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I'll double check but I'm pretty sure this 140 amp dual Voltage ALt. has the same ears as the 60 amp OEM thats on either the NHC250 or 8.3L. A lot simpler to run one alternator with one pulley and being a direct bolt in would be nice.
 

goldneagle

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The 915 Series and HMMWV run these alternators as there upgrade. 12v for lights etc. 24v for starting. Guessing it wouldn't take much to make it work but haven't personally done one. These I have come with External regulator too. There listed in the classifieds.
View attachment 622786
It depends on the physical size of the alternator. There is a limit on size when attached to the NHC250 due to the location of the oil cooler. I was going to install a 400 AMP dual voltage alternator on one of my 5 ton trucks, but there was not enough room on that side due to the location of the oil cooled.
 

73m819

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I would NOT run a duel voltage, first the cost, second, if one side (12v) goes down which may screw with the reg., (maybe over/under charge issue) which could mean a dead truck, in order to fix the 12v side, the alt. needs to go to the shop, which means that the truck is down. You can get a 24v and a 12v alts for LESS then 1 duel voltage alt, you can put a pair of spares on the shelf along with the running pair for what a good duel voltage cost
 

Tow4

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I'm adding a second alternator to my M915 so I can get rid of the pos transformer for charging the 24 volt starting batteries.
I converted a Delco 10SI I had into an isolated ground and installed a self-exciting regulator so it will not require any connections other the the B+ and B- to the second pair of batteries. Those batteries in series with the primary pair, provide 24 volts for starting and military trailer lights. It will basically operate like a CUCV charging system.
The Delco alternators are cheap and easy to convert to isolated ground so you can run two alternators without worrying about them interfering with each other.
I would do that instead of spending 100's of dollars for a dual voltage alternator or battery equalizer.
 

74M35A2

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Sometimes to do this on a V belt setup, it is easiest to drive the second alternator from the first one, meaning, you basically have a machine shop weld a 3rd pulley groove onto your existing alternator pulley, and then drive your newly added 12v alternator from the 3rd groove of the original alternator, mounting them close together. I did this to add a belt driven air compressor to my flatbed tow truck, and it has worked perfectly, and doesn't upset the original configuration of the accessory drive belt or tensioning. The A/C bracket kit is another good way, and more costly, but would give you the required mounting platform to adapt to. You could also draw off one battery, or run a DC-DC converter to act as a 12v power supply and charger for the 12v battery. I don't know why more people don't do it this way, as they have become super cheap, even the high current ones. Check the weight of the dual voltage alternator, as your original brackets may or may not like it. Also, I don't think the dual voltage units are as reliable as any of todays modern alternators are. Personally, I'd go with a single modern high quality high output 24v alternator, and then a single 12v battery connected via a battery isolator, if wanting a stand-alone 12v system.
 
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swbradley1

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Get one of these:

http://www.amazon.com/Pyle-PSWNV720-Power-Converter-Technology/dp/B003P17X8I

I have one for my 813 and someday I'll put it on. Wireloom and a few pieces of wire and a fuse and you can put it on the back of the cab wall on the passenger side. You can get different sizes but for $32 why go through all the hassle of adding stuff to the engine or welding or reengineering something. Unless you want to run dozens of devices 30Amps is more than enough to charge a cell phone or run GPS.
 

simp5782

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Has anyone added the second alternator to the Cummins 250 and if so what kind of bracket did they use ?
pics would be nice.
If you don't have an A/C compressor mounted on your truck you could use the Kenway Engineering bracket to add an alternator in the area below the power steering pump and dual run off both Power steering belts.
 

lindsey97

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Get one of these:

http://www.amazon.com/Pyle-PSWNV720-Power-Converter-Technology/dp/B003P17X8I

I have one for my 813 and someday I'll put it on. Wireloom and a few pieces of wire and a fuse and you can put it on the back of the cab wall on the passenger side. You can get different sizes but for $32 why go through all the hassle of adding stuff to the engine or welding or reengineering something. Unless you want to run dozens of devices 30Amps is more than enough to charge a cell phone or run GPS.
I bought one of the pyle converters, input is from my slave plug on passenger side with long power cord to the pyle. Output is a 12v cigarette lighter plug with 6 ft. of cord. Mine was $17 on ebay, but is only 5 amps. All I plan on powering with it is charging my phone, or powering my Garmin gps. I can transfer it from truck to truck.
 
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