HMMWV Battery Polarity Keeps Reversing?

[gimpyrobb]

Right... I'm having a difficult time finding a 24V pump locally. Any suggestions?

They are listed over on egay from 20.00 to hundreds of dollars.

 

[Action]

do you have a 100amp or 200 amp alternator with a 14v lead ran to the rear battery? Post a pic of your battery compartment with everything installed.

 

[papakb]

Using a voltage regulator to power 12 volt accessories off of 24 volts is the only safe way to go. Polarity reversal is very unusual since lead zinc batteries tend to polarize by the nature of their plates when electrolight is added. You haven't mentioned what alternator setup your running in your truck. If it's a standard 60 amp alternator it only has one hookup configuration. If it's one of the 12/24 volt alternators all bets are off since there are leads running to both batteries. If you want to run 12 volt stuff you can either use a voltage regulator to drop the 24 volts down to 12 volts safely or you can use something like a Vanner voltage equalizer that continuously monitors the batteries and balabces the loading.

Kurt
KG6KMJ

 

[gimpyrobb]

That is incorrect

A dc to dc converter or a battery equalizer is what your trying to describe.

Please try not to post wrong info.

 

[doghead]

Airtext 8131, simple as googling "24 volt fuel pump".

https://www.summitracing.com/parts/atx-e8131

I got one from carquest last time I wanted one. Napa or any other parts stores can get them.

 

[BLK HMMWV]

All the talk of a 12 or 24 volt fuel pump is a waste of time.
the vehicle was designed to run without needing one.
You need to find out what's causing your fuel delivery problem.
Have you changed the fuel filter since you owned it?
Have you checked the fuel filter/ sock in the tank on the pickup tube.
You need to find out what's causing your fuel delivery problem not force fuel through the problem.

 

[Action]

My bet is on the sock in the tank is plugged up. And, an engine will crank just fine without feul. It just won't start.

 

[dilvoy]

Try installing a new filter and water separator in the fuel filter housing first. Your flow problem is a classic sign of a restricted fuel filter or fuel line.

 

[155mm]

I had one in SFOR that was in an accident, after all the repairs were completed, called it finished, parked it on the done line, went to deliver vehicle, dead batteries, installed new batteries, it ate a PCB and another set of batteries in less than a week. It had reverse polarity at the batteries. After lots of yelling and fishing, ended up being the ground shunt was cracked on the back side. Just something else to inspect.

 

[86humv]

That is incorrect

A dc to dc converter or a battery equalizer is what your trying to describe.

Please try not to post wrong info.

Humm...When I type 24vdc to 12vdc reglulator on google, I get 24vdc to 12vdc reglulators for sale, and DC to DC coverters.....so I guess he's not wrong.

 

[gimpyrobb]

Well, its on the Internet so it must be right.

Its probably listed like that so the uninformed can find it.

 

[Jbulach]

Step-down/buck converter, could be more correct, more along the lines of a transformer, I think?

 

[NormB]

Well, its on the Internet so it must be right.
Its probably listed like that so the uninformed can find it.

26 years exposure to Nomenclature, Military, Cockeyed doesn't make looking up parts in the manuals any easier.

Spent I don't know how much time in the parts books (24P-1,2,3) trying to find fuel injector, injector, fuel or some other combination. Probably the wrong book, but it made sense to look there.

There's common language, then there's tech-speak/military jargon/engineer-think and the folks making up the somewhat indecipherable language all seem to carry a chip on their collective shoulders.

Just sayin.

 

[gimpyrobb]

Not sure what your "just sayin".


Ive been on this site trying to help folks for a little while. If you don't want help don't post or click the "ignore" button by my posts and you'll never see a post by me again.

Someone looking for something and having the correct terminology will find it faster, that was what I was offering(correct terminology).



Edit, looks like the ignore button has been eliminated, my bad.

 

[glcaines]

I had a vehicle once that behaved like yours regarding the fuel delivery. It would start up fine and idle fine. However, when driving, the engine would unexpectedly die. After coasting to a stop it would start right up again. Replaced fuel filters, mechanical fuel pump, etc. No help. Finally drained the tank and found a plastic bag in the fuel tank. It would get sucked over the the intake, kill the engine, and then drop off the intake. Very frustrating and time consuming to solve.

Additionally, I have an M35A3 that occasionally has fuel delivery issues. In this case it is caused by a check valve in the fuel line directly over the fuel tank. M35A3 trucks don't have a filter on the inlet in the tank, only a fairly course screen. The main fuel filter is located after the check valve. The symptoms are restricted speed, until eventually the engine will only idle, and then the engine won't even start. Your problem may be caused by a similar situation. You need to eliminate all possibilities in the fuel delivery.

 

[Jbulach]

Step-down/buck converter, could be more correct, more along the lines of a transformer, I think?

Hope I didn't offend anyone and doubt that it was gimpyribb 's intention either, but I can't speak for him, just an observation of his great character over the years.
I just wanted to add some terms to search, that may get you closer to the parts source instead of dealing with someone that's making a buck renaming a part something that it's not.
However I'm no expert, and as gimp was pointing out this is the internet, so MY terms may be BS as well..

 

[123mack]

Hi JLAINC, i'm just north of you in Chilton county. I have completely rebuilt the fuel system in my 1038, so if you need any help, feel free to contact me. As far as the electric fuel pump goes, I know of where one was installed in a CUCV, which has an identical fuel system. The problem arose when the diaphragm in the mechanical lift pump developed a leak. The electric pump kept on pumping,filling the crankcase with diesel fuel.

 

[JLAINC]

Okay Guys, I know it has been a while on this post, but I purchased the following 24v-to-12V converter from Amazon: https://www.amazon.com/gp/product/B003P17X8I/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I installed it in my HMMWV and both the LED lights and the following in-line fuel pump were working great: http://www.oreillyauto.com/site/c/detail/MRG0/12D/N0515.oap?ck=Search_N0515_-1_-1&pt=N0515&ppt=C0128

I went to take it on the first test drive, and 1/2 mile down the road smoke started billowing out from under my seat where the converter was mounted. I immediately stopped and shut off the vehicle. Once I was sure nothing was on fire, I pulled the 30-amp fuze on the converter, cranked the vehicle and drove it home. Today was the first time I have had a chance to take a look at it again, and I pulled the converter case off, but did not see anything that was obviously burned up. When I hooked it back up and tried to test it, nothing. So I put my multi-meter on it and found that I was only getting .46-volts on the input? When I metered my batteries, I found that the rear battery had ONCE AGAIN reversed polarity!!!

This just seems crazy to me, because the vehicle was only running for 10-15 minutes tops, so that should not have been enough time to reverse the polarity of the battery no matter what the 12-volt accessories were doing. Thus, my only conclusion is that somehow this reversed polarity happened while the truck has been sitting for more than a month! WTH???

 

[BLK HMMWV]

You must have one **** of a parasitic drain on your battery's .
Do you disconnect the batteries for storage?
Do you have a battery shut off in the circuit?
When you are hooking up the cables to the batteries do you get a spark?
Hook up all the batteries like normal except the ground to the frame. Use a meter between the negative post of the battery and the wire that goes to the frame .
See if you get a reading.
Then try it between the plus terminal and the wire going to the shunt . see if you get a reading.

 

[doghead]

https://www.batterystuff.com/blog/battery-myth-can-a-battery-reverse-polarity.html