Control Box...what is good for?

[EdMontana]

Really, what a failure in design.........replaced when I purchased my HMMWV because last owner fried a new box (he failed to disconnect the batteries) and now even after I alerted the diesel shop and even printed a sign on yellow paper and placed in the windshield "disconnect batteries before any electrical work" they still managed to fry my new S3 box.

Is there anyway to get rid off it and place a more reliable system? Why they did not engineered a fuse or something to go bad before frying the box is beyond my imagination.

 

[FireFighterHill]

Well hopefully the shop is going to compensate you for their mistake.

 

[emmado22]

I'd have the shop buy me a brand new box!

 

[EdMontana]

The shop owner, a Vet Army Mechanic, admitted their fault and will work out the difference in the labor (means, " jack up the labor " and subtract the cost of a new box).

Seems like the control box is the biggest weak point on HMMWV's since HMMWV day one, found this old article that explain, I wonder how much money went in the tubes do to this poor system...


Army Truck Enhancement Cuts Maintenance Costs

 

[papakb]

Throughout the history of the HMMWV the PCB has been one of it's weakest links and has caused more red lined trucks than anything else in the system TACOM has claimed that the military uses 25,000 of them per year. This is probably the cause of their continuing redesign of this POS. There have been at least half a dozen manufacturers and an equal number of designs. My original Prestolite lasted 26 years and you could always tell when it was working because of the comforting thud of the glow plug relay cycling. The Marines loved them too because you could kick the $hit out if it when it stopped and that gave you half a chance of it beginning to work again. LOL Later boxes went solid state and all you had was the voltmeter to tell you if the plugs were cycling. No conforting thudding. Probably the worst of the lot were the LAU boxes. These had a seperate glow plug harness and 2 engine compartment connectors. They would sometimes crank up a vehicle and if it started it would run until it ran out of fuel. Other times it would just crank until the starter or batteries died. There were a lot of vehicle fires attributed to these boxes too.


The latest Smart Start System (S3) boxes seem top be pretty good but we'll wait to hold judgement on them.


If the start switch fails, in a pinch, you can short pins S and T on the STE/ICE connector to engage the starter.
Kurt

 

[jwaller]

put it a new style EESS box. it's the latest and greatest one to come down the pipe for the V.

 

[o1951]

I could be wrong, and probably am -
Seems like this system could be changed to pushbutton. Push button energizing glow plugs for 5- 15 seconds, depending on temperature before engaging starter. On the Diesels I am familiar with, once running, glow plugs are turned off. User would let go pushbutton.

If we did this, then would not burn out expensive glow plugs.

Does anyone have a circuit schematic we could look at?

 

[papakb]

Yes, the box could be replaced with a push button to energize the glow plugs and lot's of CUCV guys have done just that. Keep in mind that by doing so you lose battery reverse polarity protection, starter engage with the vehicle running protection, and some other things designed to protect the vehicle. There's a lot more to this box than just making the glow plugs work.

Kurt

 

[jwaller]

yes and the box tells the Alt when to start charging and it cycles the glow plugs after the eng is running to try and clean them. doesn't mean I like it but thats just what it does.