HMMWV Battery Polarity Keeps Reversing?

[JLAINC]

That sock appears to be in very good shape. I think I'd leave it alone and worry about your reverse charging issue if it was me.

10-4... I just need to also fix what ever is my fuel deliver issue. I've already replaced the mechanical pump, the injector pump, and replaced the stock fuel filter system with a hi-flow Racor, and although the problem is not quite as bad, without the electric pump it will still go dead on me occasionally while I'm running down the road. I can let it sit for a few seconds and it will usually crank back up again. The faster I drive it the worse the problem is. Adding the in-line electric pump resolved the issue with fuel delivery, but I guess that is just masking some other problem?

I have to also believe that adding the 12v pump was the catalyst for the battery polarity reversal, because it started a couple months after I added it. A couple of guys have described similar issues from running 12v accessories on the HMMWV's with the old 60-Amp gens. Mine is a 7000 series serial number, so it was one of the first...

 

[ryanruck]

10-4... I just need to also fix what ever is my fuel deliver issue. I've already replaced the mechanical pump, the injector pump, and replaced the stock fuel filter system with a hi-flow Racor, and although the problem is not quite as bad, without the electric pump it will still go dead on me occasionally while I'm running down the road. I can let it sit for a few seconds and it will usually crank back up again. The faster I drive it the worse the problem is. Adding the in-line electric pump resolved the issue with fuel delivery, but I guess that is just masking some other problem?

Stupid question but since it sounds like you've checked everything else... Have you checked that your fuel tank is venting adequately? If you have the fuel cap secured and you take it off, does it make a noise like you're breaking vacuum on it?

I had a problem with my truck where the vent valve and line had some sort of sludgy white buildup preventing the tank from venting adequately and creating a negative pressure situation inside the tank.



I had noticed when fueling up, sometimes after a little driving, my fuel cap would be a little tough to take off even after loosening it but, I had never gone on a long enough drive to have much more of a problem than that. Then after a longer trip one day, after I had arrived to my destination and went to start the truck up a short time later, the truck would only crank with white vapor coming out of the tailpipe like it was a glow plug issue. I let the truck sit for a couple hours and was then able to start it up. After this, when I got home, I started doing some troubleshooting through the TM. Interestingly enough, the TM mentioned my exact condition with the fuel cap seeming to be under suction. It specifically mentioned to check the fuel tank venting system.

I checked and that's when I discovered the vent line and valve was severely clogged. No idea how or what the white sludge was but, I replaced my vent valve, valve gasket, vent line (it's just air brake line you can get from NAPA), and the vent line filter. After that, no more fuel starvation issues or having the filler cap under vacuum.

 

[JLAINC]

I checked and that's when I discovered the vent line and valve was severely clogged. No idea how or what the white sludge was but, I replaced my vent valve, valve gasket, vent line (it's just air brake line you can get from NAPA), and the vent line filter. After that, no more fuel starvation issues or having the filler cap under vacuum.

Thanks Ryan, I will go ahead and replace all of that while I've got the tank off!

 

[JLAINC]

I had a problem with my truck where the vent valve and line had some sort of sludgy white buildup preventing the tank from venting adequately and creating a negative pressure situation inside the tank.

Wow!!! I found the EXACT same issue with my vent line! The entire line is filled with a white sludge of some type which has clogged it up... Going to the parts store now to get new line. Thanks!

 

[ryanruck]

Wow!!! I found the EXACT same issue with my vent line! The entire line is filled with a white sludge of some type which has clogged it up... Going to the parts store now to get new line. Thanks!

Awesome! Glad that helped!

I wonder what this white sludge was/is? It reminds me of the mineral buildup sludge you get in your faucet strainers.

 

[kc5mzd]

There is a bacteria that grows in diesel fuel. I wonder if that could have been it?

 

[Wire Fox]

This looks like a pretty thorough summation of all the diesel fuel issues that occur: http://www.diesel-fuels.com/bad-diesel-fuel.php

Bacterial growth, water in tank, fuel forming polymer chains from recirculation... Lot of possibilities. Seems like the things to do is ensure you have a clean tank, check and replace your filters often, ensure water doesn't leak into your tank (but some will infiltrate via condensation), periodically rotate the fuel, and not using summer diesel in cold temperatures without a stabilizing additive. I'm not reveling in the idea of what my fuel lines might look like. Right now, it starts and runs just fine, but I know that I'll need some good PMCS on that system soon enough.

 

[JLAINC]

Hi Guys,

I know it has been a while on this post, but I discovered something today that might be related...

I ended up installing a master kill switch in order to overcome any potential shorts in the harness, etc... This seemed to be working fine for my battery drain issue, so I thought I would just move on from there. Once the weather started getting colder, which doesn't really happen until December in Central Alabama, I started having cold start issues. I checked my glow plugs and sure enough they were burned out, so I ordered and installed a new set today. I had 3 swollen plugs which took me a minute to remove, but finally got them all replaced. I decided to test one of the plugs to ensure my controller, relay, etc. were working properly, so I had a plug connected to the wire, and then ran a gator clip jumper that I grounded to the motor.

To my surprise, the glow plug started heating up before I even turned the ignition switch! I double checked this multiple times, and no matter what I do, if my master kill switch is in the ON position, then the glow plug heats up even when the key switch is in the OFF position.

I am now thinking that this must have been my mysterious battery drain issue the whole time! What would cause this? Bad glow plug controller, relay, key switch, or what???

Thanks!

 

[Dock Rocker]

What gp controller do you have?


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[Milcommoguy]

Testing the glow plug system the way you did is a smart move. Simple and proves what happens over and over with failed controllers. Just pay attention as plug gets HOT real FAST. Voltmeter even smarter test, less likely to burn your fingers. The power to feed the plug circuit (a relay or solid state equivalent in controller) maybe toasted. With the Stop / Run / Start switch in the STOP position there shouldn't be any voltage at the glow plug harness (any one of the eight plug wires) so this too is a problem, if I read your post correctly.

My two cents....I am thinking it's the "not so smart box controller" Control box is smoked or went for a swim (drain out water) OR something is really messed up with the engine / harness / connector.

GOOD LUCK and post what you find.

Happens every winter BOXES, PLUGS and BATTERIES,

CAMO

 

[JLAINC]

You are probably right about the "Control box is smoked or went for a swim", because I had her steering wheel deep in a creek last year. I bet that was the root of the problem...

I found the following control box and harness on ebay. Think I should start by replacing these? My harness looks like it has seen WAY better days...

ebay links removed, site rules do not allow them.

 

[86humv]

DO NOT buy that harness.....its not part of any Hmmwv anymore....the glo plug wires are part of the eng. harness since the mid 80's.

 

[Dock Rocker]

Call Michael Vaiden at Black Dog Customs and get a box with the correct temp sensor from him. He is a good guy to do business with and he want rape you on the price of the box.


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[Milcommoguy]

Follow up to my post and follow on to what 86humv noted "don't buy" I was speaking of the "glow plug harness" as in general or the eight leads leads that are integral to the complete engine harness assembly going to the eight glow plugs.

He's RIGHT on, save your money. And test and check and check again.

You're going to need it,

CAMO