Glow plug light stays on, engine won't start

[1993]

The glow plug light won't go off and cranking shows no sign of firing.
the batteries are relatively new and up until today the engine has started on the first crank.

The only thing I can think of is that I was messing around the batteries(cleaning) and accidentally shorted the positive terminal to against the aluminum surrounding. It gave a momentary spark as it just briefly touched.
I'm really hoping this is a fuse issue...?
Could that have fried something? is the "Start control box" very sensitive? does it have a fuse?

 

[Wire Fox]

The glow plug light won't go off and cranking shows no sign of firing.
the batteries are relatively new and up until today the engine has started on the first crank.
The only thing I can think of is that I was messing around the batteries(cleaning) and accidentally shorted the positive terminal to against the aluminum surrounding. It gave a momentary spark as it just briefly touched.
I'm really hoping this is a fuse issue...?
Could that have fried something? is the "Start control box" very sensitive? does it have a fuse?

That short you experienced is highly likely to be the root cause of the problem. The HMMWV does not make use of fuses on any of its stock components. Instead, it makes use of circuit breakers that are located on the right side of the steering column. These are self-resetting, so they would already have resumed normal operation at this point. An M1123 or other 4L80E-equipped HMMWV will have a manually reset circuit breaker located on the back side of the battery box just for the 12V transmission. As to your assessment, you're likely on the money for the issue. The start control box is extremely sensitive to electro-static discharge and voltage fluctuations. It's notorious for being killed when a user disconnects any of its connectors without first disconnecting the negative battery terminal, even when the vehicle is completely off.

That being said, other users have repaired various models of the start control box. It's not a task for a novice, as you're likely to do more harm than good if you don't already understand digital electronic circuits.

 

[orgnal]

The glow plug light won't go off and cranking shows no sign of firing.
the batteries are relatively new and up until today the engine has started on the first crank.

The only thing I can think of is that I was messing around the batteries(cleaning) and accidentally shorted the positive terminal to against the aluminum surrounding. It gave a momentary spark as it just briefly touched.
I'm really hoping this is a fuse issue...?
Could that have fried something? is the "Start control box" very sensitive? does it have a fuse?

Simple stuff first. Are you sure the transmission is in neutral?

McReddy

 

[1993]

so I pulled the box out and opened it up. Looks like new outside and in. It's the yellow label EESS box.
No sign of fried anything.
I closed it back up, put a little electric grease on all the connector points and reinstalled it. However I did not think to disconnect the battery before doing this, I will next time.
Anyways, It started right up on first crank as it had been doing before the scare.
Any thoughts to what happened?
maybe unplugging and plugging it back in finally got the breaker to reset?
Thanks for the replies

 

[Bravojmc]

Like everyone asks.... DO YOU HAVE A GROUNDING KIT...?

 

[1993]

Like everyone asks.... DO YOU HAVE A GROUNDING KIT...?

Not sure, looking up "HMMWV grounding kit" now..
It seems I do have what is called a "grounding block". it's what the batteries are directly connected to.
Is that the same thing?

 

[1993]

Looked further.. so i'm now guessing that what you mean by ground kit is supplemental grounding cables connecting the engine, starter, generator, and body?

 

[SCSG-G4]

Also make sure the starting relay is completely plugged in. We had a problem with Dave's HMMWV at the Gilbert parade with the same symptoms, turned out the connector was pulled out a little more than 1/8 inch from the relay. Once it was pushed back in, started up with no problems.

 

[Wire Fox]

Looked further.. so i'm now guessing that what you mean by ground kit is supplemental grounding cables connecting the engine, starter, generator, and body?

Precisely what he meant. There's full details on it as a sticky in this HMMWV forum. Literally will be the top-most topic right now. I don't think the supplementary ground kit is actually necessary, but it's what I'd like to call "good insurance." If you meticulously disconnect, clean, reinstall, and seal all of your electrical connections (highly recommended to do any time you're already doing maintenance in an area, or any time you go through deep water), you won't have a problem with everything being properly grounded. What happens is that as these corrode and otherwise start to get a poor connection, the electrical current will find another route of travel (or simply disconnect and stop functioning). When you install this supplemental grounding kit, you create an additional designated grounding path. That way, you are a lot less likely to have an ugly failure, such as having all of the alternator current flow through the PCB/EESS/S3.

If it means anything, I've just installed the grounding kit. I'd like to think that I do a pretty good job at cleaning up my connections and regularly inspecting for failures, but it's going to be that one connector that fails that I didn't catch that gets me. I also could have easily manufactured my own, but I decided purchasing was more worthwhile, that way I wouldn't have to worry about getting the tricky crimp correct of having 4 8 AWG wires all in the same terminal connection.

 

[Bravojmc]

Precisely what he meant. There's full details on it as a sticky in this HMMWV forum. Literally will be the top-most topic right now. I don't think the supplementary ground kit is actually necessary, but it's what I'd like to call "good insurance." If you meticulously disconnect, clean, reinstall, and seal all of your electrical connections (highly recommended to do any time you're already doing maintenance in an area, or any time you go through deep water), you won't have a problem with everything being properly grounded. What happens is that as these corrode and otherwise start to get a poor connection, the electrical current will find another route of travel (or simply disconnect and stop functioning). When you install this supplemental grounding kit, you create an additional designated grounding path. That way, you are a lot less likely to have an ugly failure, such as having all of the alternator current flow through the PCB/EESS/S3.

If it means anything, I've just installed the grounding kit. I'd like to think that I do a pretty good job at cleaning up my connections and regularly inspecting for failures, but it's going to be that one connector that fails that I didn't catch that gets me. I also could have easily manufactured my own, but I decided purchasing was more worthwhile, that way I wouldn't have to worry about getting the tricky crimp correct of having 4 8 AWG wires all in the same terminal connection.

Thank Foxy for the reply I was away from the forum can couldn't reply back to him.

 

[1993]

Precisely what he meant. There's full details on it as a sticky in this HMMWV forum. Literally will be the top-most topic right now. I don't think the supplementary ground kit is actually necessary, but it's what I'd like to call "good insurance." If you meticulously disconnect, clean, reinstall, and seal all of your electrical connections (highly recommended to do any time you're already doing maintenance in an area, or any time you go through deep water), you won't have a problem with everything being properly grounded. What happens is that as these corrode and otherwise start to get a poor connection, the electrical current will find another route of travel (or simply disconnect and stop functioning). When you install this supplemental grounding kit, you create an additional designated grounding path. That way, you are a lot less likely to have an ugly failure, such as having all of the alternator current flow through the PCB/EESS/S3.

If it means anything, I've just installed the grounding kit. I'd like to think that I do a pretty good job at cleaning up my connections and regularly inspecting for failures, but it's going to be that one connector that fails that I didn't catch that gets me. I also could have easily manufactured my own, but I decided purchasing was more worthwhile, that way I wouldn't have to worry about getting the tricky crimp correct of having 4 8 AWG wires all in the same terminal connection.

So I tried starting it up the other day and the same thing happened.
The "wait" light does not turn off and cranking does not fire up the engine.
I installed a wiring kit that I made at my local welding supply store. used #3 welding wire(basically battery cable) for starter-to-block and generator-to-block. Used #2 wire from block-to-dash and block-to-control EESS box bolt in engine compartment.
I made sure to clean everything with a wire brush and fine sand paper followed by generous amounts of Ox-Gard Anti-Oxidant Compound.
But the problem still exists.
as I mentioned before, when this happened before, I opened up the EESS box, it looked like new inside and out. I looked very closely at all the circuitry, it looked very clean. And of course it worked when I closed it back up and reinstalled it.
I still think that whatever is going on is caused by the momentary short to ground that happened when cleaning the battery box.
Maybe it's a breaker issue?
Any thoughts?

 

[Frapguy]

I have the same problem. Ever figure out what it is

 

[porkysplace]

I have the same problem. Ever figure out what it is

Test Your EESS box.
Have you downloaded the free TM's ?
They have troubleshooting sections in them.
[h=1]TM's for the M998 series[/h]A good source on how to use the TM's;
How to use/read Technical Manuals

 

[1993]

I removed the EESS box, opened it up, it looked like new inside(no burn marks), put it back together.
I then installed additional much heavier gauge grounding cables, from the block to the box, also to the starter, to the alternator, and to the back of the dash.
I made sure to unplug the battery first!
As I recall it still acted up the first time I tried starting it.
But it's been working fine ever since. actually I think the glow plug light goes out sooner than it did before the whole experiment. About 10 seconds.
Good luck Frapguy!