Bet you $1.00 you cant figure this out! PCB EESS SSI HMMWV

[decodeme2]

Solutuion: My hmmwv will only start using the old style prestolite control box.

History: 2 years ago my 1987 m1044 would not start. (all orginal)figuded the old prestolite box went bad. Ordered a new green label kds box from kaskar. Installed it and a new grounding harness. Would not start. Figured i got a new (bad) box. Bought a new yellow ssi and temp controler on ebay. Installed it per instructions and "nothing". Would not start. Figured i got another bad box.

Asked a friend if he had any boxes and he said his old prestolite box worked when he replaced it with a new kaskar green label box. I installed his old box and the hmmwv started right up!
This worked great until now, 2 years later my hmmwv will again not start.

I again installed a new green label box and 2 ssi yellow boxes and "nothing" it will not start. As of now im looking for a "good" prestolite box to replace my bad prestolite box.

Question: Is my wireing harness different than others?
Why will my hmmwv only start with the orginal pres. Boxes?

Does anyone have a 'nos" prestolite box for sale?..
Does anyone have a "good" used prestolite box for sale ?
If so, are you going to red ball in gelbert pa...?

Thanks in advance!
Kevin...in maryland...

nsn: 6110-01-395-9585 Prestolite Control Box

 

[2Deuces wild]

She is a cranky old MV, Set in her ways Only wants the parts she's use to. Make her happy. Give there what she wants and she will run again

 

[tanhmmwv]

When you install any of the boxes, are your batteries COMPLETLY disconnected? You CANNOT install a PCB with batteries connected, you will blow the inside of the PCB. The plugs are poorley designed and will short out the PCB. try this next time and let us know.
Also, if you are using a GPC, that could be bad or loose connections will do this. good luck.

 

[tanhmmwv]

Also, I have a used prestolite and a nartron box, I am not going to red ball though. make an offer.

 

[decodeme2]

Thanks guys,
I disconnected the batteries, everytime. My buddy says, sice the wait light cycles correctly it gots to be the glow plugs..I will test them. replace them with non-swell ones im told. Will have more info this weekend..Im told the old box will cook the plugs..we will see..
Kevin..

 

[Retiredwarhorses]

Decode
You need a Ground Harness....Check out my other Reply Post.
My 85 did same...Installed Harness and it fired right up.
But "yes" Check or change out your GP's for new Kascar non swells
and install new EESS...Yellow or Green label. Yellow lable needs matching Temp sensor in Water crossover tube, Green label does not...I just have found the Green labels don't act right....Like the Wait light will come on regardless of engine temp.

 

[Chief_919]

When you say will not start, do you mean it will not crank, or it cranks but will not start?

 

[decodeme2]

Hey guys, update..
I installed a grounding harness from kascar..It cranks, and will not start without eather,.,I installed a new in the box ,Netron(sp?) box and sensor as a last resort before buying a prestolite control box....Yes i put a ohm meter on the glowplugs and nothing..The light cycles 4 secs cold 1st try and nothing(ohm's) after that it just flickers..also (nothing)...I bet if i put a new Prestolite sensor and/or box in it, it will start right up!..
Man this thing is a Pain in the @ss...It should be stright forward..
Yes The glow plugs checked out fine..No they are not the non-swell type..
Should not matter without voltiage...
Kevin...

 

[Retiredwarhorses]

If you pull out one glow plug, install it into the connector, run an alligator clip to the threads and the other end to ground, turn the key to wait. That glow plugs tip should turn either bright orange or get hot as hell. if not and you have replaced everything else, I would still replace those GP's.
Have you used a Volt meter to see that you have 24v at the connector when you turn the key?

 

[decodeme2]

Great idear, I will try it..Yes i did, nothing..I will also install a new GP..Will let you know tomorrow..Thanks again,....

 

[tanhmmwv]

I had a nartron box that was new and NO GOOD. Try this, with all the glow plug wires unplgged from the glow plugs. Put the key on and put a test light to the GPC connection. 1 wire should have power. If you have power there, plug it in (diconnect batteries before doing this)and then check a glow plug wire. If you do not have power at the glow plug wires, you have a bad PCB.

 

[decodeme2]

Bingo!,
Bad Box, installed another and new glow plugs, and works like a charm..,
I had a bad (new) box..Some times the ebay deals are not such a good deal..!..
Thanks again!, I owe you a dollar..!..Do you take paypal?...!
Kevin..

 

[Wile E. Coyote]

A basic digital voltmeter with 'diode test' or just an ohms/resistance scale is a great tool for checking glowplugs. Basically, set the meter to any ohms range or diode test, hook one probe up to nice, clean engine metal -- touch the other probe to the tip of the glow plug after removing the glow plug harness lead -- and see what the reading is. Basically you'll generally get some reading that wants to change as a good glow plug loads up -- but a reading of nothing/0.00 indicates the plug is trashed. Lots of trashed plugs on the first gen systems, many times because the glow plug temp sensor itself is crap (as opposed to the PCB.)

Several glow plug sensors were used (these are the cylindrical things that screw into the coolant crossover with the multipin plug affixed to the top), and evidently any of them with the black plastic upper body or any of them with an OD green metallic body are time-bombs waiting to cost you a lot of money and frustration. I've changed a bunch out with the newer Nartron ones from, I think Front Line Military Vehicles, and haven't had a glow plug failure since despite several different types of early-gen PCBs installed.

The PCBs fail because, usually, the relays they used are craptastic. I've had some other miscellaneous electronic components fail in them too relating to turning on the WAIT light, but mostly it's just the old-fashioned relays that have performed one open-close too many. They usually fail open though and not closed, which you'd expect if you'd fried all your glow-plugs and the Temp sensor isn't to blame.

Others have mentioned grounding issues and that's another bitch. I've had a couple with inop glow plug circuits where the engine wasn't grounding - at all. In fact, one owner dropped by with one of them complaining about glow plugs and I took a test light - put it between the body metal of the Humvee and the engine block - cycled the glow plugs - and watched the test-light light up! Not good. Hooked a nice big jumper cable between body metal and engine block and everything worked as designed.

 

[tanhmmwv]

glad to hear it!! what box did you install? does it use the GPC?