Just purchased 99 m998 and can’t start

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08hmmwv

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Brooklyn ny
Hey I recently purchased a 1999 humvee 6.5 4speed from a person in Indiana which had purchased it from hummerkingz out in miami on nov 2019. When my transporter picked up the vehicle he stated that the car was already running and he pulled right up to the trailer. I received the vehicle today (24 degrees) and cannot start it. I tried on delivery and the battery was completely dead so i purchased yellow top duel purpose battery. i turn the nob and wait light turns on for a split second and right off, after that no matter how many times I turn the nob it wouldn’t even turn on for a split second. So I went ahead and tried to start the vehicle and it cranked with no start. The person kept this vehicle in his barn and told me I need to replace the glow plugs if I keep it out doors but it wouldn’t make sense to me if the glow plugs aren’t even getting power. He gave me an engine block heater but I don’t want to rely on a block heater all the time I travel. I ordered this on eBay because a lot of forums say it might be an issue https://www.ebay.com/itm/KDS-Temperature-Sending-Unit-TSU-PCB-CR-2696A-HMMWV-M998-Glow-Plug-Controller/143487430168?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649. I am stuck here and not sure what to do.
Please help out. Thanks in advance
 

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Coug

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This is a common issue, and there are dozens of threads started here on a regular basis for "HMMWV no start"

That being said, sounds like you have a bad control box. This is a relatively common issue, the fix is to replace the control box with a newer version, and replace the temp sending unit (TSU) that goes with it.
You can NOT mix and match control boxes and temp sending units, so you will want to make sure that it matches your controller. (though it seems to be the controller failing a lot more often than the TSU)

You'll also want to check and make sure that the glow plugs haven't failed as well.


Some people have built manual glow plug controllers, or torn apart and rebuilt their old boxes, it all depends on your level of skill.
 

BLK HMMWV

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You said the battery was dead as in " one " and you replaced "it" with a yellow top.
Also you are turning a " knob" what " knob" are you turning.
More then likely your glow plugs need to be replaced as well as the control box and the TSU.
Also you need to make sure that both of your batteries are fully charged.
It's best that they both be the same size and type.
When you start working on the Control box and TSU you need to make sure you disconnect the batteries first.
Do a search for HMMWV No Start as suggested above
 

Ajax MD

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Mayo, MD
Hey I recently purchased a 1999 humvee 6.5 4speed from a person in Indiana which had purchased it from hummerkingz out in miami on nov 2019. When my transporter picked up the vehicle he stated that the car was already running and he pulled right up to the trailer. I received the vehicle today (24 degrees) and cannot start it. I tried on delivery and the battery was completely dead so i purchased yellow top duel purpose battery. i turn the nob and wait light turns on for a split second and right off, after that no matter how many times I turn the nob it wouldn’t even turn on for a split second. So I went ahead and tried to start the vehicle and it cranked with no start. The person kept this vehicle in his barn and told me I need to replace the glow plugs if I keep it out doors but it wouldn’t make sense to me if the glow plugs aren’t even getting power. He gave me an engine block heater but I don’t want to rely on a block heater all the time I travel. I ordered this on eBay because a lot of forums say it might be an issue https://www.ebay.com/itm/KDS-Temperature-Sending-Unit-TSU-PCB-CR-2696A-HMMWV-M998-Glow-Plug-Controller/143487430168?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649. I am stuck here and not sure what to do.
Please help out. Thanks in advance
Not to discourage you from asking questions, but also consider reviewing the tech manuals. Winter is a great time to flip through them.
Here's the link: https://www.steelsoldiers.com/threads/hmmwv-technical-manuals-if-you-need-it-its-here.189594/

For the M998, focus on the manuals ending in -280-10, -280-20, etc. The other manuals are for the heavier trucks.

Especially read through the -280-10, which is the "Operator's Manual." It will help you learn normal and abnormal indications and basic troubleshooting.
 

papakb

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Ajax MD, The "other manuals" aren't for heavier trucks, they're the next level of service for them. This makes it important to pay attention to the front cover page where it tells you what trucks the particular manual is for. The TM 9 2320-280-xx are manuals for the HMMWV itself. The TM 2320-387-XX manuals are for shelters and the TM 9 2320-237-XX manuals are for the engines. In general, the higher the suffix numbers the higher the maintenance level. The -10 manuals tell you how to do the basic checks and operations on the trucks that drivers need to know. The -20 series manuals are basic maintenance manuals that will walk you thru first tier operations like getting reluctant trucks running and changing out major assemblies. The -3X manuals take you into the second tier maintenance activities like how to change or repair minor level assemblies and or rebuild components. These are all in the TM, technical manual series of books. There is another series called TB or technical bulletin. They come into play when working on a specific item, how to install a SINCGARS radio set for instance. The third set of manuals related to the trucks are the MWO series. These are Maintenance Work Orders. They'll tell you how to install things like the 3 point seatbelts or the dual pull rear brake upgrades.

But as you said, winter is a great time to read them as almost anything you want to know about the HMMWV has been discussed and the troubleshooting flow charts are designed to help the FNG fix his truck.
;) And keep in mind that they're all free courtesy of the US Government and when was the last time you got anything free from them?
 
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papakb

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It's good to review this stuff occasionally because of all the new HMMWV owners out there that don't have any military background. Nobody teaches you this stuff in high school or college.
 

Ajax MD

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It's good to review this stuff occasionally because of all the new HMMWV owners out there that don't have any military background. Nobody teaches you this stuff in high school or college.
I drove 'em but I was a "twidget" (electronics tech) hauling and deploying towed sensor platforms and comm shelters. I wanted to turn wrenches with our maintenance dept. but they weren't interested in showing me anything. Now I have to teach myself.
 

papakb

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I did missile fire control aboard ship but went into the Navy with a heavy electronics and mechanics background. For the last 50 years I've done military radios, generally green because the gray ones were too heavy to collect! LOL
 

BLK HMMWV

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I never was in the service . But I soon learned what HMMWV stood for .
And once mine retired from the Marine Corp the Acronym changed from High Mobility Multipurpose Wheeled Vehicle to High Maintenance Money Wasting Vehicle.
Nobody in there right mind should own one if they can't learn to wrench on them.
It's not really so much high maintenance if you keep up on it, but it does require you keep up on it.
 

08hmmwv

New member
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Brooklyn ny
If the control box is no good I cant seem to understand how the seller got it started to drive onto the trailer because the tow truck told me she was running when he got there . Should I change the kids 2696A first before changing the control box? Which control box is best to order? And is possible a link to it. Thank you
 

BLK HMMWV

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Grab a cold one and read through this.

The batteries could have been toast but the guy you bought it from used the nato plug and jump started it. that's why it was running when he arrived to pick it up.
Trying to start it over and over with low batteries could have damaged the control box.
Start with the easy stuff.
Disconnect the batteries and charge them one at time.
While batteries are charging check each glow plug with a ohm meter.
If any don't ohm out then replace them .
personally if you find even one bad one I'd replace them all .
Make sure you use 24 volt glow plugs.

Make sure you have a good ground connection.
If you don't have a the upgraded ground harness on the truck build or buy one.

Once you can confirm you have 2 fully charged batteries and all your glow plugs are good.
you can test the other stuff.
 

kzeyus

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Before spending money, especially on an expensive s3 box I'd trouble shoot a bit. Test your glow plugs and see if any are good. Check Batt voltage. Do you have a stock ignition switch or has it been replaced with a key switch? Do the glow plugs get 24v when you turn key, etc.
 

WillWagner

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Grab a cold one and read through this.

The batteries could have been toast but the guy you bought it from used the nato plug and jump started it. that's why it was running when he arrived to pick it up.
Trying to start it over and over with low batteries could have damaged the control box.
Start with the easy stuff.
Disconnect the batteries and charge them one at time.
While batteries are charging check each glow plug with a ohm meter.
If any don't ohm out then replace them .
personally if you find even one bad one I'd replace them all .
Make sure you use 24 volt glow plugs.

Make sure you have a good ground connection.
If you don't have a the upgraded ground harness on the truck build or buy one.

Once you can confirm you have 2 fully charged batteries and all your glow plugs are good.
you can test the other stuff.
WHAAAT?? You are sounding like a wrench! (y) 🔧 🍻
 

Retiredwarhorses

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It’s very common I get trucks delivered too the shop that have dead batterie, reason is, the transport companies
inadvertently leave the start switch in the run position, kills the batterie, kills glow plugs etc...
3 reasons for a flashing wait light with that box, bad box, bad TSU or all glow plugs blown, the box has to see a minimum
number of plugs to sense it’s draw in amps is correct. so Start checking all the GP’s.
 
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