Jump start question

1985 - Present, Questions, discussions, regarding anything related to the Humvee. (NO AUCTION or EBAY)

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RockHillWill
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Jump start question

Post by RockHillWill » Mon Nov 06, 2017 3:34 am

As stated previously, I am starting my first Humvee project. I won a bid on GovPlanet, and the ad stated that the truck started and restarted at the time of inspection, but I am concerned about how to jump start the 24v system if I arrive and it will not start then. I am picking it up with a 40 ft lowboy tractor trailer rig. It is in Richmond, Va. and is likely to be cold at that time as well. Thanks!


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DockRocker
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Re: Jump start question

Post by DockRocker » Mon Nov 06, 2017 3:45 am

RockHillWill wrote:As stated previously, I am starting my first Humvee project. I won a bid on GovPlanet, and the ad stated that the truck started and restarted at the time of inspection, but I am concerned about how to jump start the 24v system if I arrive and it will not start then. I am picking it up with a 40 ft lowboy tractor trailer rig. It is in Richmond, Va. and is likely to be cold at that time as well. Thanks!
The obvious answer is to carry two New or known good batteries that have a full charge with you and if it doesn’t start just swap the batteries.

Many of the pickup sites will slave start the truck for you but I would ask them if someone would be available to jump you off at the time of pickup.


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RockHillWill
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Re: Jump start question

Post by RockHillWill » Mon Nov 06, 2017 5:03 am

Thank you for your response. I am able to handle the two 12v batteries, but in looking at some Humvees, it looked like they had only one case/housing and I keep seeing something about a 'slave' connector/cable???

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DockRocker
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Re: Jump start question

Post by DockRocker » Mon Nov 06, 2017 6:00 am

RockHillWill wrote:Thank you for your response. I am able to handle the two 12v batteries, but in looking at some Humvees, it looked like they had only one case/housing and I keep seeing something about a 'slave' connector/cable???

There is one battery box under the passenger (commander) seat. In it there are two 12 volt batteries wired in Series to get to the needed 24 volts to power the truck. If those batteries are dead just pull them out and drop in new ones. A normal civilian battery isn’t going to take up the required space in the compartment as they are much smaller but you can just pull the others out and replace them to start and load the truck. When you get it loaded either secure the civi batteries for the trip of pull them out of the box so they want be bouncing around unsecured.

Just in front of the battery box on the outside where the passenger would sit there is a small round port that is the slave port. This is effectively the idiot proof way to jump start a military vehicle. You plug a slave cable into this port and then plug it into a running military truck or generator’s slave port and you can jump start the truck. Google NATO slave cable and NATO slave port.

I would recommend that you download the technical manuals for your new hmmwv and read them until you are blue in the face. I believer you are looking for the -24 manual.

Before you do anything but drive it onto the trailer there is some maintenance that must be done or you can potentially cost yourself a fortune in parts and labor. You need to service the Motor, transmission, transfer case, and your heated hubs at a minimum. I would also suggest you instal a grounding harness to prevent any major electrical / glow plug problems.


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RockHillWill
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Re: Jump start question

Post by RockHillWill » Mon Nov 06, 2017 7:30 am

That's precisely the info that I was looking for. I can take it from there. I have downloaded every applicable TM that I can find that pertains to both the M1026 vehicle and the M1102 trailer that we have recently acquired. I review these TM's to the point that I have made my own 'index' to make locating information that I need or have seen in previous viewings. I have read about the grounding system, and will move that towards the top of the list of PM work to do.

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Re: Jump start question

Post by DockRocker » Mon Nov 06, 2017 7:54 am

Check out Jeff Cress. He has quit a few videos and how to’s on gear report. Here is a link to his harness installation.

http://gear-report.com/hmmwv-upgrades-m ... ng-harness

Also here is a video

https://youtu.be/NORo30wIdqk



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Kurt Lesser
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Re: Jump start question

Post by Kurt Lesser » Mon Nov 06, 2017 9:43 pm

I've just been through a battery replacement for probably the 5th time in all the years I've owned this truck and I have to tell you that unless you have some great contacts the 6TN/6TL batteries out there do not last worth a darn for the money they cost. The Optimas are good batteries as are the AGMs but if they go flat on you because of a short or leakage or some kid left your light switch on they are a royal PITA to get back up. My solution this time around was to go with a set of civy 24F batteries. I chose them because if you get them with flat tops (no battery filler caps) they will fit well into the battery tray and the original battery hold down bracket will keep them in place.

Doing some research on them it turns out there are northern and southern 24F batteries out there for some ungodly reason but look for the ones that are flat topped and you'll be good to go. They're less than half the price of the 6TN/6TLs and have just a tad less CCA but since I've installed them the truck has started fine and besides, they come with a 3 year free replacement warranty. The 3 sets of Interstate 6TLs that I ran lasted about 26 months on average and Interstate only warranties them for 24 months or less because they're a "special usage" battery. That's BS. As for "originality", nobody sees your batteries under the passengers seat anyway.

As for a newly acquired truck, you want to service all fluids. Brake fluid, coolant, and all lubricants. It's also beneficial to change out the thermostat. Replacing all belts and hoses will save you down the road and doing all of this will give you much better familiarity with your new toy. Make sure all your battery connections are clean and tight and the supplemental grounding harness can be a lifesaver, if not a PCB and alternator saver. Like they say in the trades, RTFM. They're full of indispensable knowledge that can save your butt in the field. Your going to learn a lot about vehicle maintenance with this one because no Chevy dealer will even look at it so a good set of tools is in order. I probably spent at least an hour a month on a creeper under mine just looking for loose bolts and hardware and checking for leaks.

Mostly, enjoy it. They're a ton of fun to drive around and today you get lots of thumbs up from all kinds of folks.
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RockHillWill
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Re: Jump start question

Post by RockHillWill » Tue Nov 07, 2017 2:51 am

Thanks Kurt. That is the useful inform nation that I am looking for. I am preparing as best I can. This will be my last bucket list project, and I want to do it as well as I can. I do have tools. I built stock cars for 25 years and restored Model A's for 15 years. Wife is into this project as well, so I am hoping to enjoy it. Help like yours will make it easier. THANKS!

Would you care to share the brand name that you chose?

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Kurt Lesser
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Re: Jump start question

Post by Kurt Lesser » Tue Nov 07, 2017 9:17 am

RHW,

Having the wife onboard will make this project go 100% faster! Let us know if there's anything we can assist with.

Kurt
Kurt Lesser
US Navy, 1969-1975
M996A1 Ambulance w/M101A3 Trailer
M274A2 Mule
M151A1 Mutt w/M416B1 Trailer
M890 Crew cab

desmodromic
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Re: Jump start question

Post by desmodromic » Wed Nov 08, 2017 6:12 pm

I always bring a set of optima yellow tops with me, but worst case scenario you can have the GP rep forklift the Humvee onto the trailer. I have had it done over a half dozen times, including recently at the Richmond base.
93 M998 Seabee
95 M1025A2 GMV x4
99 M1045A2
99 M1123A2
02 M1025A2 GMV
09 M1165A1
11 M1165A1
93 M923A2 x2
97 M1078
02 M1031M1
00 MEP-803A
10 M1102


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