Shut hmmwv off and 10 seconds later wouldn't restart?

[racingjoe66]

[FONT=&quot]Okay guys, me and my son were out checking minnow traps this evening and cruising through snow out in the field with the HMMWV and having fun in the ditch. When were heading back to the house from out in the field and got to the field drive that is going up hill and with a 3 foot snow drift in it we stopped and shut the truck off to put it from H to HL and when I attempted to restart it within 10 seconds. I noticed the wait to start light didn't light up and then I tried to start it, the truck wouldn't even click or crank over or anything at all, absolutely no noises of anykind. The lights all come on like they should and everything. I did notice that when I didn't have the brake lever activated that when I tried to start it the break light would light up and go back off when i turned the ignition switch to off. But when I did activate the parking break lever the break light would stay solid with the ignition switch in the run and start position. I have switched through all the gears in the transfer case as well as the transmission and making sure the trans is in Nuetral still with no help and even tried starting in gear and nothing. I also pulled the transmission shifter towards me to try and see if the saftey switch was acting up and still nothing. I checked the battery connections and they were all loose so I tightened them all up and that made no difference. I checked the voltage and it was 23.3 volts. I checked the voltage when flipping the ignition switch to attempt to start and the voltage doesn't drop at all or even glitch. I also did notice that the heater fan will come on now with the ignition switch in the off position and what i recall from before this happened was that the fan would only come on if the truck was running and or the ignition switch was in the run position but not in the off position like it is now. I did crawl under the truck with the ignition switch in the run position and jumped the starter solonoid and the truck cranked over but would not fire at all.[/FONT]

[FONT=&quot]Any ideas what happened? The more I am thinking about this and with the wait light not coming on and the heater fan being able to be turned off and on even with the ignition switch in the off position is that somehow the truck is thinking it is still running........? Ignition switch or nuetral saftey switch?[/FONT]

[FONT=&quot]thanks for any help!

[/FONT]okay guys I have an update. When I checked the batteries last night they were 23.3 volts. now this morning when I went to see if it would start they were at 18.7 volts. Then I fired up the skid loader and moved all the snow for 200 feet to get to it to be able to pull it out and up to the shop. I just checked them now and they are at 17.6 volts. Still no wait to start light and everything else. So what ever the issue is, is drawing the batteries down too. If it is the neutral safety switch can that cause the electrical drain and trick the computer to thinking the truck is still on?

thanks guys!

 

[Bulldogger]

You definitely have some kind of short, with the heater fan able to run and the stop/run switch in Stop.

The wait to start light will often NOT come on if the motor is good and hot. That isn't necessarily a fault to investigate.

The Brake light should be on if the switch is in Run and the Brake set, and off otherwise. But, the brake light and/or parking brake don't make a difference in starting, in my experience.

The trans definitely has to be in neutral, and the starter will not engage on my HMMWV if it's not in neutral.


It sounds like you might have jarred some wires while snow-bogging, hit some snow chunks or some sticks, etc.



First I'd check the mess of wires that come off the positive battery terminal and lead out of the battery compartment under the right hand side of the body and then to the starter and up into the engine compartment and cab. Look for wires torn or visibly displaced. It definitely sounds like some kind of short at mains power. My HMMWV has a spiral protector over these made of thick uninsulated metal wire. IF you have that and it was jammed into the cable connections, it would be shorting things out.

Definitely disconnect and recharge the batteries while you investigate this.


Bulldogger


PS. Also, please change the color of the font in your post, if you can, as it's dark like the website background and hard to read.

 

[Carrera911]

Probably a dead EESS box. Someone more experienced can chime in but that's what it sounds like. To bypass it and start the truck you have to give the fuel shut off solenoid 24 volts to keep the engine running and then jump the starter.

And to shift the transfer case, you don't have to shut the truck off. Stop and put the trans in neutral. Then slam the transfer case into whatever gear quickly. Leave the t/c in neutral too long and the gears lose their speed sync and then the truck has to be shut off to change the gear.

 

[racingjoe66]

I got the negative post on the rear battery disconnected and the batteries charging. As soon as I unhooked it I heard a very noticible loud clunk like a relay turning off somewhere but couldn't tell exactly where it came from. And I also noticed that on the heat sink in the battery box one of the small wires was loose so I tightened it also.

sorry about the color of the words. didn't notice my bad.

thanks for the input on not having to shut the truck off, the first time I was running it this fall when I tried it would grind so since then I always just shut it off to do so.

Also as soon as I unhooked the batteries I noticed the voltage of each started slowly climbing back up on there own. As for the wait light it wouldn't come on even this morning with the truck good and cold.

 

[Retiredwarhorses]

A bad EESS will cause all sorts of unexplained issues...the list I have uncovered is so vast I can't even list them all.
people ask all the time, "want spare parts should I have on hand?" Well, an EESS box and TSU is the number one on my list. It's easy for me as I have about 5 NOS S3's on hand at any one time, but I use one a week.
that clunk your heard is the relay in the EESS box de-energizing

 

[Jakob1944]

A bad EESS will cause all sorts of unexplained issues...the list I have uncovered is so vast I can't even list them all.
people ask all the time, "want spare parts should I have on hand?" Well, an EESS box and TSU is the number one on my list. It's easy for me as I have about 5 NOS S3's on hand at any one time, but I use one a week.
that clunk your heard is the relay in the EESS box de-energizing

The first thing I bought was a PCB a month before the EUC cleared........I'm going to put it in a Faraday Cage for when 'The' day comes

 

[racingjoe66]

The truck is running guys. I charged up the batteries and rehooked them up and the wait light came on and it fired right up. Charging at 27.0-27.1 volts. I let it warm up and shut it down and it restarted right back up like it should. Looks to be the master relay in the PCB somehow was stuck and when I took all the power away it came unstuck and is now working, but for how long is anyones guess.

 

[wheelspinner]

The truck is running guys. I charged up the batteries and rehooked them up and the wait light came on and it fired right up. Charging at 27.0-27.1 volts. I let it warm up and shut it down and it restarted right back up like it should. Looks to be the master relay in the PCB somehow was stuck and when I took all the power away it came unstuck and is now working, but for how long is anyones guess.

Have you installed an auxiliary grounding harness? I wonder if a ground jump from the EESS would have been an interesting test now that we see the finished product.

 

[Bulldogger]

Cleaning up wires and grounds seems in order.

Glad she's running again.

Bulldogger