Anderson connector attached to heavy gauge wires passenger side seat...???

[Tiwaz]

Hmmmm, this would give me pause to think. Why did you have to use the jumper box? Are the batteries draining, or bad? Do you have a parasitic drain? Whichever it is, I would concentrate getting the issue fixed rather than spending hundreds of $$ on that pack and having to rely on it.

Ohh yeah.... the problem has been addressed: Replaced alternator, unfortunately I ended up with a 200A from a 400A one but it seems to be working for now (I have only had it since Saturday) but the problem remains, you can always find you batteries depleted because you left lights... accessories... or something else connected to USB outlet for a couple of days so I believe it's always good to have a box that will crank the engine when the batteries are low for whatever reason.

 

[BLK HMMWV]

You should be glad you have the 200 amp and not the 400 amp.

 

[Tiwaz]

You should be glad you have the 200 amp and not the 400 amp.

Can you elaborate....?

 

[TOBASH]

I have become convinced that every HMMWV and Hummer should have a 500-1000 Amp cutoff switch. That ends the issues with battery drain.

 

[Coug]

Can you elaborate....?

400 amp is massive overkill, very heavy, bulky, expensive to get a regulator for, and takes up a lot of space in the engine bay. There are a lot of repairs/maintenance you can do working around the 200 amp that you have to pull the 400 amp out of the truck in order to accomplish.

 

[Tiwaz]

400 amp is massive overkill, very heavy, bulky, expensive to get a regulator for, and takes up a lot of space in the engine bay. There are a lot of repairs/maintenance you can do working around the 200 amp that you have to pull the 400 amp out of the truck in order to accomplish.

Well as it turns out a week or 2 into the 200A alternator downgrade, in spite of the fact that my volt meter inside the car reads anywhere between 27.9 and 28.3 (at higher RPM) my batteries are not charging very well in fact this morning it took 3 trys to get my engine going, the first two the starter motor did not turn at all with the third one it barely turned but enough to start the engine. The needle on my generator gauge inside is some times pretty much on the line between the yellow and the green but most of the time while traveling is slightly below the center (or smacked in the center) of the green zone with the volt meter gauge always above 28.0. At this point I don't know if the new 200A generator is overwhelmed or maybe there is a different problem...???
ohhh... forgot to mention that I keep my A/C shut down because if I turn it on my gauge starts reading 27.7V so, having already battery problems I do not want to aggravate the whole charging system. All I know is that I was not having any kind of problem with the old 400A generator until it quit on me. Maybe timing coincidences....? I ended up making a jump start harness that goes straight into the jump starter via Anderson connector and straight to the battery terminals on the other side to avoid passenger seat removal.
Does a 200A generator have a way to adjust (via internal potensiometer screw) the voltage output...? I think the 400A one did.

 

[Coug]

Starter motor not turning and the alternator are 2 different things entirely. The truck will start and run without any alternator in it at all, and has zero effect on how well it starts.

The 200 amp alternator is still massive overkill for the power requirements of these trucks. Your standard car with all it's electronics will easily run on a 60 amp alternator at 12V, which is equivalent of 30 amps at 24V. All you need power for while running is operating the lights, transmission, keeping the fuel shut off solenoid open, and recharging the battery power used while cranking. The batteries handle the cranking. Size of alternator output will just affect how long it takes to recharge the batteries.
The larger alternators are mostly there in case auxiliary equipment gets installed later.

To me it sounds like you have a bad connection somewhere. It might be on the positive wire between the batteries and the starter, or it might be a loose connection on the ground cable side of things such as a loose bolt at the DC shunt in the battery box (I've seen multiple people say they had issues with those bolts being loose)

The regulator for the 100, 200, and 400 amp alternators is sealed and no adjustment possible.

Compare voltage output at the batteries and at the alternator output. They should be 100% identical. If they aren't, especially when you do things like turn on the aircon, then you have a bad connection somewhere that needs taken care of. Bad connections such as corroded connections, or loose connections making poor contact, are probably the main issue people have with the HMMWV electrical system.

 

[Tiwaz]

Starter motor not turning and the alternator are 2 different things entirely. The truck will start and run without any alternator in it at all, and has zero effect on how well it starts.

The 200 amp alternator is still massive overkill for the power requirements of these trucks. Your standard car with all it's electronics will easily run on a 60 amp alternator at 12V, which is equivalent of 30 amps at 24V. All you need power for while running is operating the lights, transmission, keeping the fuel shut off solenoid open, and recharging the battery power used while cranking. The batteries handle the cranking. Size of alternator output will just affect how long it takes to recharge the batteries.
The larger alternators are mostly there in case auxiliary equipment gets installed later.

To me it sounds like you have a bad connection somewhere. It might be on the positive wire between the batteries and the starter, or it might be a loose connection on the ground cable side of things such as a loose bolt at the DC shunt in the battery box (I've seen multiple people say they had issues with those bolts being loose)

The regulator for the 100, 200, and 400 amp alternators is sealed and no adjustment possible.

Compare voltage output at the batteries and at the alternator output. They should be 100% identical. If they aren't, especially when you do things like turn on the aircon, then you have a bad connection somewhere that needs taken care of. Bad connections such as corroded connections, or loose connections making poor contact, are probably the main issue people have with the HMMWV electrical system.

Coug, thanks for the explanation, I was already thinking that I had to bring the old 400A to get rebuilt somewhere but what you say makes sense, a 200A generator should be plenty of juice for a Humvee with basically no heavy duty accessories or aux equipment in it.

When you suggest to check compare voltage between battery and alternator output, would that be with the alternator spinning and the volt meter lead on the yellow terminal on the regulator or is that the fat RED cable right on the alternator its self (the one I believe goes to the starter) sorry for not being familiar with who is who at the alternator but I am just beginning to learn about this having had an Humvee for just a few weeks.

 

[Tiwaz]

Starter motor not turning and the alternator are 2 different things entirely. The truck will start and run without any alternator in it at all, and has zero effect on how well it starts.

The 200 amp alternator is still massive overkill for the power requirements of these trucks. Your standard car with all it's electronics will easily run on a 60 amp alternator at 12V, which is equivalent of 30 amps at 24V. All you need power for while running is operating the lights, transmission, keeping the fuel shut off solenoid open, and recharging the battery power used while cranking. The batteries handle the cranking. Size of alternator output will just affect how long it takes to recharge the batteries.
The larger alternators are mostly there in case auxiliary equipment gets installed later.

To me it sounds like you have a bad connection somewhere. It might be on the positive wire between the batteries and the starter, or it might be a loose connection on the ground cable side of things such as a loose bolt at the DC shunt in the battery box (I've seen multiple people say they had issues with those bolts being loose)

The regulator for the 100, 200, and 400 amp alternators is sealed and no adjustment possible.

Compare voltage output at the batteries and at the alternator output. They should be 100% identical. If they aren't, especially when you do things like turn on the aircon, then you have a bad connection somewhere that needs taken care of. Bad connections such as corroded connections, or loose connections making poor contact, are probably the main issue people have with the HMMWV electrical system.

Coug, YOU WERE RIGHT !

Upon further review at the "Instant Replay" I found the bolt for the ground totally loose and the ground strap not even connected, I am even wondering how I did not get some smoke do to the on/off contact at the generator. I put everything back and later on when I go home from work I'll see if anything changed.
THANK YOU !

 

[Retiredwarhorses]

First thing I see in that pic is the extra 14v tap wire going somewhere, the 2nd is the pulley on the Gen, I see visible groves where the belt should be.

 

[Retiredwarhorses]

And…200amps isn’t technically overkill, the AC alone is 30amps, you technically per the TM cannot run a red dot system without a 100amp, but that was old guidance when A2’s were relevant…most modern trucks run 130amp on up to 400amp.

 

[Tiwaz]

First thing I see in that pic is the extra 14v tap wire going somewhere, the 2nd is the pulley with on the Gen, I see visible groves where they belt should be.

Yes Retiredwarhorses, very true, the 14V tap I believe is going to the 12V GPS speedometer and if you notice all the way at the top of that picture you will see the A/C compressor pulley being the one that forces the skinny serpentine belt (I don't know who made that choice (I just work here )

 

[Mrgior31513]

And…200amps isn’t technically overkill, the AC alone is 30amps, you technically per the TM cannot run a red dot system without a 100amp, but that was old guidance when A2’s were relevant…most modern trucks run 130amp on up to 400amp.

I agree with Coug. A heavy duty high output alternator for a comparable Ford Powerstroke or Dodge Cummins is about 195 amps, usually running around 125 for stock. These are for civilian trucks that have a lot more electrical stock and heavy duty designed for a lot more extras like extra powered stereo systems, offroad lights, ect. 200 amps is a lot of juice for a basic diesel, 400 amps is overkill.

 

[Coug]

I agree with Coug. A heavy duty high output alternator for a comparable Ford Powerstroke or Dodge Cummins is about 195 amps, usually running around 125 for stock. These are for civilian trucks that have a lot more electrical stock and heavy duty designed for a lot more extras like extra powered stereo systems, offroad lights, ect. 200 amps is a lot of juice for a basic diesel, 400 amps is overkill.

plus the difference between 12 and 24V, so those 195 and 125 amp alternators would be the equivalent of about 60 and 100 amp in 24v

The only real difference is the aircon on the HMMWV has electric fans for the condensers, where civilian vehicles typically have it as part of the cooling stack, eliminating the need for additional cooling fans (and many decades of technology improvement compared to the HMMWV as well)

 

[Coug]

Coug, YOU WERE RIGHT !

Upon further review at the "Instant Replay" I found the bolt for the ground totally loose and the ground strap not even connected, I am even wondering how I did not get some smoke do to the on/off contact at the generator. I put everything back and later on when I go home from work I'll see if anything changed.
THANK YOU !View attachment 927679

glad to help out. I believe that strap was also loose on my truck when I received it, so another common failure location.

 

[Mrgior31513]

plus the difference between 12 and 24V, so those 195 and 125 amp alternators would be the equivalent of about 60 and 100 amp in 24v

The only real difference is the aircon on the HMMWV has electric fans for the condensers, where civilian vehicles typically have it as part of the cooling stack, eliminating the need for additional cooling fans (and many decades of technology improvement compared to the HMMWV as well)

That occurred to me as I went back out to break, I was running the watts through my head and 400 amps on 24v is more than enough to power a medium sized house. At 9600watts, it is a tremendous amount of juice.