Humvee 400 Amp voltage regulator

[jim1131]

My humvee has blown 2 voltage regulators and im on the 3rd one already. It seems that each time they went bad after accidentally shorting one of the battery cable under the passenger seat and its getting expensive to keep buying them. I have installed a grounding harness and im thinking that I should install a bus fuse somewhere between the regulator and one of the 3 terminals (IGN, AC, +14). I would like some advise as to which terminal should be fused and what amperage fuse I should use.

Any help is appreciated and I thank you in advance

 

[Mogman]

Quit shorting the terminals under your seat!
The system is fine as is, you cannot engineer out mistakes.
You should also get rid of the 400A alt

 

[Milcommoguy]

Did I read this correctly ??? ... " It seems that each time they went bad after accidentally shorting one of the battery cable under the passenger seat ...."

I would say you got to fix this shorting thing. I see owners without battery hold down, Batteries in sideways, terminals / posts with little to none clearance to the metal box, etc. Not saying this is the situation here. Shorts circuits in the battery box when following the proper layout shouldn't be an issue IMO.

Fuses could work... and could be just a band-aid to the problem. Pictures please....

Not looking to be snarky, but this is the first time I have heard of this and AMG / Government would have been all over this one.

Shorts circuits and the sparks are going to fly, regulators are going to die, CAMO

 

[jim1131]

Quit shorting the terminals under your seat!
The system is fine as is, you cannot engineer out mistakes.
You should also get rid of the 400A alt

I know its not common but I have had this problem twice already . I think I will put a 25 Amp buss fuse on all three terminals and hopefully I wont need to spend another $400 next time around.

 

[Milcommoguy]

I wold like to understand what is really going on?? Pictures are very helpful... Like picture worth a thousand words, LOL.

I would like dive deep to understand what up here. A little more data would be helpful.

This keeps happening, as you say and on number three... There is something missing from this problem / story line.

You are right, It is not common. What is common is all the trucks have alternator, From time to time a failure can occur. Q, What else is blowing up?

Three strikes is not a good batting average for HMMWV's, CAMO

 

[Mogman]

I know its not common but I have had this problem twice already . I think I will put a 25 Amp buss fuse on all three terminals and hopefully I wont need to spend another $400 next time around.

That is not likely going to save you, there are two big 200A cables connected to the regulator through the alternator, the answer is to mark everything so you stop making the same mistake over and over.

 

[Coonass77]

You definitely need to address the shorting problem, that's your root cause. Additionally, $400 is less than half of what I'd expect to pay for a replacement regulator, so if you're truly only paying that much for them, I suspect it's potentially an aftermarket part that might not have as robust short circuit protection as an OEM regulator.

 

[TOBASH]

1) FIX THE DAMNED SHORT! TIE DOWN THE BATTERIES! PURCHASE A PLASTIC BATTERY BOX!!!!!

2) Get rid of the 400 Amp unless you live in a flood zone. Get. 200 Amp conversion setup.

3) FIX THE FOUNDATION BEFORE YOU WORK ON THE ROOF! FIX THE SHORT!!!!!!!!

 

[Maxjeep1]

1) FIX THE DAMNED SHORT! TIE DOWN THE BATTERIES! PURCHASE A PLASTIC BATTERY BOX!!!!!

2) Get rid of the 400 Amp unless you live in a flood zone. Get. 200 Amp conversion setup.

3) FIX THE FOUNDATION BEFORE YOU WORK ON THE ROOF! FIX THE SHORT!!!!!!!!

I’m confused about 2)? I am in the process of getting rid of my 400amp. I can’t figure out the flood zone part of 2)

 

[TOBASH]

I’m confused about 2)? I am in the process of getting rid of my 400amp. I can’t figure out the flood zone part of 2)

If you live in a disaster zone, then a 400 amp alternator is an 1000 watt generator. A generator and an additional sine wave power inverter are great ideas to keep the house running. 75 amps of power for the fridge and the HVAC.

 

[Maxjeep1]

If you live in a disaster zone, then a 400 amp alternator is an 1000 watt generator. A generator and an additional sine wave power inverter are great ideas to keep the house running. 75 amps of power for the fridge and the HVAC.

Hahaha I got it now. I wasn’t thinking about running house off of it and thinking more about it being a better anchor…

 

[Mogman]

If you live in a disaster zone, then a 400 amp alternator is an 1000 watt generator. A generator and an additional sine wave power inverter are great ideas to keep the house running. 75 amps of power for the fridge and the HVAC.

You missed a zero, 400X28=11200W

 

[Coug]

even the 200 amp gen is good for 5kw of output, which is more than enough to make it through an emergency with the right setup.

 

[royg]

You missed a zero, 400X28=11200W

Interesting. I always though of the 400amp unit as insanity from a vehicle perspective. But as a contingency option for home during an outage it's kinda attractive. Anybody done that? What does it take? Is it as simple as using the slave port connected to an ac inverter or does it require some more involved wiring on the hmmwv?

 

[Coug]

Interesting. I always though of the 400amp unit as insanity from a vehicle perspective. But as a contingency option for home during an outage it's kinda attractive. Anybody done that? What does it take? Is it as simple as using the slave port connected to an ac inverter or does it require some more involved wiring on the hmmwv?

In theory the slave port is capable of 500 amps power. I don't know if for the HMMWV the cables connecting the slave port to the batteries are capable of that, but if you did a double run of the cables directly to the batteries (or to wherever the generator cables connect to) then in theory, yes, you can just do it to the slave port.

I believe trucks with shelters/equipment that utilize the power of the 400 amp gen are hardwired to the batteries (I know my BEOD with a 1kw inverter wired direct to the batteries.)

 

[Coug]

The cost of the inverter and the cost of the wiring on the 24V side would be ridiculous. You're talking an inverter that costs more than most portable generators do for even a cheap chinese one. For a quality inverter with that output, you could pretty much buy an MEP-803A


For 400 amps of sustained power you need wither size 500 cable, or a double run of 3/0 wire. The double run is cheaper/easier to find and more flexible.
You would be better off in this case having the inverter in the HMMWV and running a 240V run to whatever you want to power, as you're now talking 40-45 amps peak sustained output vs 400

quick check showed size 500 to be over $13.50 per foot and 3/0 to be under $6 per foot (THHN/THWN-2). Battery cable doesn't seem to come in sizes larger than 4/0, so a double run of 3/0 would be most cost effective.

The ideal option as I see it is to already have an inverter and 24V battery bank installed at the house, then just use a slave cable to charge the bank up as needed. You'd be limited by the size of the cabling, but you'd also only be running the engine/generator at a lower load and not trying to max the output.

 

[Mogman]

The cost of the inverter and the cost of the wiring on the 24V side would be ridiculous. You're talking an inverter that costs more than most portable generators do for even a cheap chinese one. For a quality inverter with that output, you could pretty much buy an MEP-803A


For 400 amps of sustained power you need wither size 500 cable, or a double run of 3/0 wire. The double run is cheaper/easier to find and more flexible.
You would be better off in this case having the inverter in the HMMWV and running a 240V run to whatever you want to power, as you're now talking 40-45 amps peak sustained output vs 400

quick check showed size 500 to be over $13.50 per foot and 3/0 to be under $6 per foot (THHN/THWN-2). Battery cable doesn't seem to come in sizes larger than 4/0, so a double run of 3/0 would be most cost effective.

The ideal option as I see it is to already have an inverter and 24V battery bank installed at the house, then just use a slave cable to charge the bank up as needed. You'd be limited by the size of the cabling, but you'd also only be running the engine/generator at a lower load and not trying to max the output.

Not to mention it would probably be the least fuel efficient generator ever, but it is fun the think about.
HMMWV but no MEP or other means to generate emergency power? seems the acquisition order is a little out of whack..

 

[Coug]

Not to mention it would probably be the least fuel efficient generator ever, but it is fun the think about.
HMMWV but no MEP or other means to generate emergency power? seems the acquisition order is a little out of whack..

I think it's more of an initial idea that won't pass the reality check phase of the planning.
Fun to consider what you can do with it, but too expensive to implement.

as for efficiency, one of the guys near me just got an old 2 stoke diesel generator up and running for the fun of it, so using the HMMWV might not be the least fuel efficient method for power generation.

 

[Mogman]

I think it's more of an initial idea that won't pass the reality check phase of the planning.
Fun to consider what you can do with it, but too expensive to implement.

as for efficiency, one of the guys near me just got an old 2 stoke diesel generator up and running for the fun of it, so using the HMMWV might not be the least fuel efficient method for power generation.

If it is an old Detroit they are very fuel efficient, they are nasty, slobbering, oil leaking beasts but easy on the diesel.

 

[jim1131]

You definitely need to address the shorting problem, that's your root cause. Additionally, $400 is less than half of what I'd expect to pay for a replacement regulator, so if you're truly only paying that much for them, I suspect it's potentially an aftermarket part that might not have as robust short circuit protection as an OEM regulator.

Not aftermarket but used OEM regulators when I can find one available