HUMVEE completely dead! Bad PCB or ????

[shawnshumvee]

Originally posted...

Was planning on swapping out my custom Ignition light from a Red to a green one (because it would have just look better) and that's when my issue happened. Last January i installed my own custom keyed kill switch as an alternative to the keyed ignition switches sold on eBay and elsewhere, as those type were not appealing to me for a few reasons, nevertheless, the idea worked perfect never had an issue. The way that it was designed is, if you would turn the key a red light would light up indicating that the humvee is activated (in other words.. completing the electrical circuit) and then you would continue to start the humvee as you would normally. The keyed kill switch was basically killing the voltage to the start switch. Once the key was inserted and turned this would complete the circuit thus allowing the Humvee to be started in the normal fashion and i added a light to the whole project and it was working great, but at the time i installed the custom switch i only had red lights in my shop so i used one. well every light on my dash cluster is green so it bugged me and i wanted to swap out the red light for a green one so i bought one and went to go pull the red light out and when i did i guess one of the metal connectors on the back came off and started arking and some smoke came out from behind the dash and now the whole truck is dead. It's like there isn't any batteries in it, nothing is working NOTHING! i don't even see any melted wires or anything. like a dummy i thought i could just swap the lights, kind of like a plug and play method boy was i wrong, i should have just unhooked the batteries like i normal wound have done. is there any in-line fuses? Any help would be SOOOOOO greatfull!

 

[Action]

Put the shifter in N. Try to start.

 

[shawnshumvee]

UPDATE!

After trouble shooting my rig all night i was able to bring it back to life, well kinda. So like my original post said, when changing out a simple plug -n-play light i sparked a wire connector against the metal dash and something started smoking, after that the beast was DEAD, STONE DEAD. Not even a single light! NOTHING! So i started researching, texting my buddies (who also have M998's) and reached out to SS for support. So I researched the not so user friendly TM's and done all the testing which was required, i ( unhooked the batteries and tested the battery stunt, hooked the batteries back up and tested the E pin from the Engine canon plug and also tested the Body canon plug for continuity and after all that i was sure it was the PCB. So after a few minutes of some foul langue (a Stupid $500-$600 mistake will cause some people to use foul language) so i conceited defeat and went to reinstall the PCB back in the humvee (batteries were unhooked) and call it night. So has i was doing just that, it strongly occurred to me there is simply no electric/power coming into the truck. So i simply said ... "lets give it some juice." So knowing that the 11A wire is an important main wire, i hooked hot a hot wire from the batteries directly to the 11A wire ( i think is was 11A?) on the start switch. Next, i turned the switch to the run position and to my surprise, the wait light illuminated (that was a REALLY good feeling) and after the light went out i went to start the truck and it started right up! Yeah, like nothing ever happened! Yeah pretty strange i think? so i tested all my instruments and everything works as it should accept for the brakes. I don't have brake lights. I step on the pedal and nothing happens. So I'm currently researching that issue. When i had the PCB out I did remove the 4 screws on the body connector just to see if i could get a better look inside the PCB and smell for burnt electronic components. that's as far as i went, i didn't feel like drilling out rivets. You can see that the E prong is burnt (see pictures) and i don't know if this damage was Pre or post? Meaning was it like that or did i do it? Oh, and i did not smell a hint of smoke in the PCB. So Let me know what you guys think if the PCB is Shot and could be the reason i lost brake lights or no. And simply put can a bad PCB cause the Humvee to be completely dead like there isn't any batteries in it and then all of the sudden work again? My understanding is the PCB is either Good or it's bad no in between? Maybe this is the first? I don't know?

 

[shawnshumvee]

Put the shifter in N. Try to start.[/QUOTE

My rig is always in Neutral with brake applied never left in any gear but also explored the neutral safety switch just for the heck of it but it wouldn't matter because the safety switch would only stop the engine from being started wouldn't have anything to do with lights and other body accessories, correct?. this truck was COMPLETELY dead and a faulty neutral safety switch wouldn't cause a complete dead truck. Any how it's up and running like normal accept for a hot wire running to 11A on the start switch and no brake lights. Still working on it.

 

[TOBASH]

Apparently PCB has been documented by another member to partially fail:

https://www.steelsoldiers.com/showt...-plugs-burnt-out-and-swollen-in-2-hours/page2

 

[shawnshumvee]

Apparently PCB has been documented by another member to partially fail:

https://www.steelsoldiers.com/showt...-plugs-burnt-out-and-swollen-in-2-hours/page2

Yeah it looks that way. but the good news is the glow plugs are cycling, well, the pulsating of lights and the alternator gauge says so.
I have no power to the brake light switch.

 

[shawnshumvee]

Is there a way to reset circuit breakers specifically # 2.

 

[TOBASH]

I wish you well brother.

There is also an electrical forum under restoration on Steel Soldiers.

Maybe you might ask there if anyone understands the HMMWV wiring and schematics and might help.

First maybe check your brake light wires with a multimeter with and without someone pressing the brake pedal.

Good Luck,

T

 

[shawnshumvee]

I wish you well brother.

There is also an electrical forum under restoration on Steel Soldiers.

Maybe you might ask there if anyone understands the HMMWV wiring and schematics and might help.



First maybe check your brake light wires with a multimeter with and without someone pressing the brake pedal.





Good Luck,

T

Thanks for all your help.

 

[doghead]

There is also an electrical forum under restoration on Steel Soldiers.
Maybe you might ask there if anyone understands the HMMWV wiring and schematics and might help.

Actually, that is what we call "cross posting" and it's against the site rules.

Once you start a thread, we expect you to post all pertinent info there, not re-post elsewhere.


This is the correct forum for your Humvee issue.

 

[brushhippie]

Oh my goodness...not against site rules! lol I am sure posting something like this is as well...now where is that smiley with the fingers...get the po leese in here!

 

[tage]

oh look at that corrosion. the cool thing about burnt electronics that they'll still conduct electricity, but barely. looks like just a bad ribbon. open the box and see if you have anything else burned up.

I would be cautious of just slapping in a new box without determining what caused this one to fail first. Do you have a ground harness installed??

 

[TOBASH]

Actually, that is what we call "cross posting" and it's against the site rules.

Once you start a thread, we expect you to post all pertinent info there, not re-post elsewhere.


This is the correct forum for your Humvee issue.

Never meant to create an issue.

Just trying to help a guy with an electrical demon.

Apologies

 

[shawnshumvee]

oh look at that corrosion. the cool thing about burnt electronics that they'll still conduct electricity, but barely. looks like just a bad ribbon. open the box and see if you have anything else burned up.

I would be cautious of just slapping in a new box without determining what caused this one to fail first. Do you have a ground harness installed??

Open the PCB, Ok, is there anything i should watch for or is there any special way (beside exercise care) when opening the PCB? You are correct about being a bit caution on just installing a different (and over priced) PCB. The reason i agree with that is because what i did was "VERY" minor, very trivia, very quick! Yes, i no it doesn't take much to fry the PCB but come on, you know what i mean? I mean, Like who hasn't sparked a wire once or twice in their life time and in doing so, got lucky and didn't even blow a fuze. I just can't believe that little spark good do that but it sure does seem like it did?? Are your referring to a Ground harness? If so then No, i have not. This Truck was absolutely flawless in it's mechanical department so i never felt the need to do it, " if it isn't broken why fix it?" However, in the light of all my research and the price of the PCB i did get a little worried and now i feel that the PCB is like caring a cartoon of eggs so better not press my luck and install a better ground harness and do everything i can do to protect that carton of eggs. I have read about the Ground harness and it will be done just has a cautionary measure. Moreover, i was told that the original 60 Amp alternator ( is is the one i have) is a time bomb waiting to explode? Some say these alternators were prom to over charging and wiping out everything special the PCB. In your opinion is this fact? if so I'm thinking about swapping that out as well.
Thank you

 

[shawnshumvee]

Never meant to create an issue.

Just trying to help a guy with an electrical demon.

Apologies

No biggie, heck, i didn't even know there was an issue brewing?

 

[TOBASH]

TAGE makes an excellent point about a bad ribbon.

The way to repair a bad ribbon in many cases is to use paint on auto defroster electrical paint. It will complete many circuits well.

My apology was for Doghead/Moderator. You're cool Shawn. It was my mistake not yours.

 

[shawnshumvee]

TAGE makes an excellent point about a bad ribbon.

The way to repair a bad ribbon in many cases is to use paint on auto defroster electrical paint. It will complete many circuits well.



[h=2][/h]
My apology was for Doghead/Moderator. You're cool Shawn. I was my mistake not yours.

Yes! Conductive Paint! The same stuff to repair broken rear defrosters. Why didn't i think of that? Well that why i Love this Site. You can't find that wisdom in a TM, well, at least i don't think you can? nevertheless, I'm going to embark on a journey to the unknown ( A.K.A...the PCB) and see what i can do. But i do have another update, i was able to get the brakes lights working. so the rig is back to normal accept i have to keep a hot wire connected to the11a wire on the start switch for everything to work. .
But Thank's man.

 

[shawnshumvee]

Also when i remove the PCB and do what i have to do with it and when I get ready to reinstall the PSB what is recommend for moister control at the body canon plug and engine canon plug? Dielectric Grease or....?

 

[TOBASH]

If you just need to jumper an external wire, I would leave the PCB alone, because that seems NOT to be the problem IMHO.

 

[shawnshumvee]

If you just need to jumper an external wire, I would leave the PCB alone, because that seems NOT to be the problem IMHO.

Yeah i have to run a hot wire but be for my little mishap , the truck was fine and it didn't need a hot wire, so i need to know what happened and why it needs a a hot wire. The 11A wire runs from the start switch into the Body canon plug which is connected to the PCB and that's where i have that scorch mark. So i'm thinking (it's within the realm of possibility) that's why i have to supply my own power to the start switch because the PCB is cooked in that area?