KDS green label PCB COOKED!!!!

[tanhmmwv]

While driving home, I noticed a burning smell and the alternator gauge NOT charging.
A few minutes, literally 2-3 min., as I a was pulling into the driveway, I noticed the glow plug light and park light were lit up, NOT GOOD.
I parked the truck and shut it down. I had a bad feeling and about 10 minutes later, went back to check on it.

The plug at the PCB under the dash was HOT!, opened the hood and the plug at the PCB was HOT too!
The wiring at these 2 connections were warm.
I had to put a glove on to disconnect both plugs from the PCB.

has anyone had this happen to them?
does this look like it is isolated to the PCB?
could there be an issue with the alternator, engine harness, body harness?

any diagnostic help is greatly appreciated..... I am a novice with a multi-meter
I used a multi-meter to test the engine wiring harness continuity, seems to be working properly following to the TM instruction.
but I am not quite confident.
tested harness plug at PCB to the GPC and 1 wire to the alternator.

is there a way to be sure the BODY harness is good?
is there a way to be sure the engine harness is good?
Is there a test I can do to be sure?
again more detail, and photos would be a GREAT HELP!


....

 

[tanhmmwv]

forgot to mention.... all 8 glow plugs came out, were not swollen and checked with a multi-meter = still good!

 

[gimpyrobb]

I'd pull the relay out and open it up. Looks like it went bad. I see some caps that are bad too.

 

[juanprado]

make sure battery is disconnected.

Probably it was time for the magic smoke to release.

Replace box and temp sensor/GPC (green box does not matter as wire is not used so if you replace with another green label, no need) to new ees style

 

[tanhmmwv]

forgot to mention, I did disconnect the batteries and they are both checked out and good.
ok, could the alternator have crapped out and caused this you think? or maybe a short in the harness?

 

[gimpyrobb]

Im leaning toward the relay getting stuck on, thats why I said to autopsy it. If your lucky its just a box issue.


OT
This is why I'm not a fan of electronics in MVs. Never had these issues with my deuce or 5ton. I'm sure at the time it was an awesome answer to "some issue" but now, they are problematic.

 

[juanprado]

found these 2 interesting articles.

Major points of failure analyzed by army is non military grade solenoids and boxes not sealed weather proof.

Also, Search the hmmwv section as Greg 86humv did a nice thread with all the types and pictures of the boxes and senders.

 

[Action]

For anyone else reading this. If you have some major electrical problems or smoke or burning smell, it might not hurt to go ahead and disconnect the batteries, not just park and turn it off.

Wasn't there an early version of the PCB that was catching HMMWVs on fire?

 

[tanhmmwv]

while looking at the harnesses, I noticed this chaffing on the body harness behind the steering wheel.
looks like the U-joint was rubbing the harness. it did not go all the way into the wires though.
May have caught this just in time!!
do you think putting a rubber hose over this will be good enough?

 

[tanhmmwv]

UPDATE:
thank you to everyone for the input/info and help!
there is allot of info out there....

checked the harnesses (engine and body), both good, alternator, good.
glow plugs were good, but put new ones in.
fired up and so far so good!
I ended up going with the LAU tech. box
why would you do that you ask....
I had this box in my first HMMWV which I drove for 14 years from 1994-2008, put 46k miles on it and did not have any issues.
hoping I have just as good luck with this one.
I like the separate glow plug wires AND
if this one craps out, I will be going to the momentary/manual glow light switch.

that said...
my dad has the old style, prestolite or nartron in his hmmwv and hasnt had an issue.
He's had that truck since 1995, in 2013 we replaced the frame.
86 frame was rotted beyond repair, most likely from beach landings
(ALLOT of sand came out of both frame rails in 1995 when started rebuild)

my opinion: PCB's are LUCK of the draw/hit or miss, who know's
but GROUNDING seems to be the culprit in most cases.
thanks again!

 

[Retiredwarhorses]

UPDATE:
thank you to everyone for the input/info and help!
there is allot of info out there....

checked the harnesses (engine and body), both good, alternator, good.
glow plugs were good, but put new ones in.
fired up and so far so good!
I ended up going with the LAU tech. box
why would you do that you ask....
I had this box in my first HMMWV which I drove for 14 years from 1994-2008, put 46k miles on it and did not have any issues.
hoping I have just as good luck with this one.
I like the separate glow plug wires AND
if this one craps out, I will be going to the momentary/manual glow light switch.

that said...
my dad has the old style, prestolite or nartron in his hmmwv and hasnt had an issue.
He's had that truck since 1995, in 2013 we replaced the frame.
86 frame was rotted beyond repair, most likely from beach landings
(ALLOT of sand came out of both frame rails in 1995 when started rebuild)

my opinion: PCB's are LUCK of the draw/hit or miss, who know's
but GROUNDING seems to be the culprit in most cases.
thanks again!

A LAU box? A box removed from the supply system due to fires and other issues.
good choice...funny, but I’ve intalled so many S3 EESS’s ive lost count, never had a bad KDS mfg’dS3, but have however had 2 bad Nartron S3’s and both exhibited the same problem.

What I see day in and day out in the shop is customers being cheap on box selection...buying used off eBay etc..

 

[86humv]

Alot of trucks used the Lau box way back....not all burnt up, but the ones that did used the Lau box.

 

[Retiredwarhorses]

Alot of trucks used the Lau box way back....not all burnt up, but the ones that did used the Lau box.

You are correct, most did not, but it was enough of a concern to Sh*t can the box by TACOM. The KDS S3 has so far been out standing.
kinda goes hand in hand with the Gigital light switch ...the so called replacement for the 3 lever, those have toasted a few trucks as well. I say, “why take the risk”