M998 Was Alive, But Now Is Dead

[HUNvee]

New update on HMMWV #2 - It's running, but the voltmeter stays in the yellow. Tested another GPC (just plugged it in while it laid on top of the engine - and, yes, I disconnected the batteries), but that wasn't the issue. Voltmeter still in the yellow. Connected multimeter to batteries while engine was running to rule out a bad voltmeter. No voltage change when revving the engine. A buddy of mine who's a mechanic in the National Guard says it sounds like the generator and not the PCB or GPC. It's a 200A model, so I changed the regulator before hauling that heavy monster out of the engine bay. Same result. Looks like the generator gets changed out next week.

No new progress on HMMWV #1. Trying to get #2 out of the building and parked in the compound.

When my battery was low, it took 4-5 minutes for the charging to start. If I turned on the blower, it stopped again. Are your batteries good?

 

[hawk-aggie]

When my battery was low, it took 4-5 minutes for the charging to start. If I turned on the blower, it stopped again. Are your batteries good?

Charged them, but may change them out. Easier to do that than haul that heavy beast of a generator out of the engine bay.

 

[hawk-aggie]

Chapter 1 - Green HMMWV (continued)

This is the one that fried at least one PCB that we believe was caused by a faulty starter. Just received today, the kit to help us remove the broken starter bolt. Any way, I was installing a new windshield washer reservoir/pump. It came without one. I found that some numbskull connected the two wires that are supposed to be connected to the washer reservoir to each other under the dash. I've looked at the schematics, but couldn't tell if that could have been a contributing factor to the issues we've been having. Thoughts?

UPDATE: This truck has been a pain in the butt. A lot of work has gone into it to get it ready to sell - New Protective Control Box, New Glow Plugs, New Auxiliary Ground Strap, New Starter, New Power Steering Pump, New Fuel Pump, New Fuel Injection Pump, New Windshield Washer Pump, New Batteries, Fresh Oil & Filter, Fresh Antifreeze, and Fresh Transmission Fluid.

It is now running very well, but it is cold natured - even in 100 degree weather. On the first start of the day, I have to slowly work the "gas" pedal up and down from fully depressed, after depressing it to the floor when I first turn the ignition switch to the run position. After that first start, it doesn't seem to have any issues starting right up without touching the throttle at all. I think there is an issue with the cold start circuit, but I don't know how to diagnose that. Any tips on that would be appreciated.

10/26/22 UPDATE: Got this one finished, running and SOLD!!

 

[Mullaney]

UPDATE: This truck has been a pain in the butt. A lot of work has gone into it to get it ready to sell - New Protective Control Box, New Glow Plugs, New Auxiliary Ground Strap, New Starter, New Power Steering Pump, New Fuel Pump, New Fuel Injection Pump, New Windshield Washer Pump, New Batteries, Fresh Oil & Filter, Fresh Antifreeze, and Fresh Transmission Fluid.

It is now running very well, but it is cold natured - even in 100 degree weather. On the first start of the day, I have to slowly work the "gas" pedal up and down from fully depressed, after depressing it to the floor when I first turn the ignition switch to the run position. After that first start, it doesn't seem to have any issues starting right up without touching the throttle at all. I think there is an issue with the cold start circuit, but I don't know how to diagnose that. Any tips on that would be appreciated.

.
So... I understand the PITA part of doing repairs. When you consider that this truck is maybe twenty years old and was driven hard and put up wet by the previous owner - maybe it isn't as awful as it could be? You have spent a couple thousand bucks and maybe a hundred hours or so working on it. Eventually the problems disappear one by one as you make repairs. Are you sure it is time to get rid of it? At about the time you might get to start enjoying it...

Okay, and so you can have a laugh or offer a four letter word comment - I'd give you a hundred bucks for it.



Keep laughing. It makes people wonder what you have been up to.

 

[Mogman]

UPDATE: This truck has been a pain in the butt. A lot of work has gone into it to get it ready to sell - New Protective Control Box, New Glow Plugs, New Auxiliary Ground Strap, New Starter, New Power Steering Pump, New Fuel Pump, New Fuel Injection Pump, New Windshield Washer Pump, New Batteries, Fresh Oil & Filter, Fresh Antifreeze, and Fresh Transmission Fluid.

It is now running very well, but it is cold natured - even in 100 degree weather. On the first start of the day, I have to slowly work the "gas" pedal up and down from fully depressed, after depressing it to the floor when I first turn the ignition switch to the run position. After that first start, it doesn't seem to have any issues starting right up without touching the throttle at all. I think there is an issue with the cold start circuit, but I don't know how to diagnose that. Any tips on that would be appreciated.

Sounds like you still have a glow plug issue, have you put a voltmeter on one of the glow plug wires to make sure it is getting juice? does the wait light come on for 6-10 seconds?
I am not 100% sure but at 100 deg I don't think the cold start circuit even comes into play

 

[Maxjeep1]

Sounds like you still have a glow plug issue, have you put a voltmeter on one of the glow plug wires to make sure it is getting juice? does the wait light come on for 6-10 seconds?
I am not 100% sure but at 100 deg I don't think the cold start circuit even comes into play

Few times I have went to first start my m1123 and light goes off immediately and I try it again and it goes off. This was in 95+ days so I think you are right Mogman….

 

[Mogman]

One of my boxes has a little tizzy fit now and again, but because I have a dash lamp connected to one of the glow plug wires I can see it is actually going into after glow mode where it is "flashing" the glow plugs on and off, I give it about ten seconds and they get warm enough for the engine to start right up.
This only happens to one of my boxes and then only after sitting for several weeks, I rotate out my boxes whenever I do an oil change.

 

[hawk-aggie]

.
So... I understand the PITA part of doing repairs. When you consider that this truck is maybe twenty years old and was driven hard and put up wet by the previous owner - maybe it isn't as awful as it could be? You have spent a couple thousand bucks and maybe a hundred hours or so working on it. Eventually the problems disappear one by one as you make repairs. Are you sure it is time to get rid of it? At about the time you might get to start enjoying it...

Okay, and so you can have a laugh or offer a four letter word comment - I'd give you a hundred bucks for it.

View attachment 875727

Keep laughing. It makes people wonder what you have been up to.

The whole process hasn't been too bad. It's just that when I was about to button everything up and move the truck to the compound, the starter flaked out on me and fried the PCB, which created other issues as well. Actually, with our surplus source for parts, we've got maybe $300-$400 in it. We have 15 Humvees right now. Five are operational (2 are for sale), 1 other is a parts truck, 2 others (not running) are for sale, and the rest are waiting for some love. Selling them is one revenue stream for our museum.

 

[Mullaney]

The whole process hasn't been too bad. It's just that when I was about to button everything up and move the truck to the compound, the starter flaked out on me and fried the PCB, which created other issues as well. Actually, with our surplus source for parts, we've got maybe $300-$400 in it. We have 15 Humvees right now. Five are operational (2 are for sale), 1 other is a parts truck, 2 others (not running) are for sale, and the rest are waiting for some love. Selling them is one revenue stream for our museum.

.
Nice to know more of the story.
Have you listed any of them for sale in the CLASSIFIEDS section here?

It might be a heck of a deal - buying a HMMWV from a museum - and writing a check to a Non-Profit Organization.
Dropping Uncle Sugar out of the picture would make everyone except those who collect taxes happy.
AND they still end up with their blood money once the truck moves into the stream of commerce.

Thanks for not going "bonkers" about my earlier comment.

 

[hawk-aggie]

The whole process hasn't been too bad. It's just that when I was about to button everything up and move the truck to the compound, the starter flaked out on me and fried the PCB, which created other issues as well. Actually, with our surplus source for parts, we've got maybe $300-$400 in it. We have 15 Humvees right now. Five are operational (2 are for sale), 1 other is a parts truck, 2 others (not running) are for sale, and the rest are waiting for some love. Selling them is one revenue stream for our museum.

.
Nice to know more of the story.
Have you listed any of them for sale in the CLASSIFIEDS section here?

It might be a heck of a deal - buying a HMMWV from a museum - and writing a check to a Non-Profit Organization.
Dropping Uncle Sugar out of the picture would make everyone except those who collect taxes happy.
AND they still end up with their blood money once the truck moves into the stream of commerce.

Thanks for not going "bonkers" about my earlier comment.

I don't have the level of authorization to post classifieds. Buying one of our HMMWVs can not be considered a donation in the eyes of the IRS, but the money does go to a good cause.

 

[hawk-aggie]

Sounds like you still have a glow plug issue, have you put a voltmeter on one of the glow plug wires to make sure it is getting juice? does the wait light come on for 6-10 seconds?
I am not 100% sure but at 100 deg I don't think the cold start circuit even comes into play

Glow plug voltage is ok, but I may check all of them again. Wait light acts normally. Typically, I would agree with you regarding the cold start circuit. I think I might go back and check some wiring connections to be sure a couple haven't been switched in all the commotion.

 

[hawk-aggie]

Glow plug voltage is ok, but I may check all of them again. Wait light acts normally. Typically, I would agree with you regarding the cold start circuit. I think I might go back and check some wiring connections to be sure a couple haven't been switched in all the commotion.

Glow plugs are getting voltage. On to checking fuel flow, cold start and fuel shutoff when I get a chance.