Search results for query: eess

Start your Humvee, open the hood, and undo the plug on the engine side of the PCB protective control box/EESS smart box. If the engine stops, then it is possible that your problem is the box. If the engine continues running, then you have some other problem.

NOTE: I'm going to be using the term "smart" box in referring to the EESS. Don't get twisted about semantics. Our 1994 M1097 that I'm working on has an electrical issue. Engine is 6.5L, transmission is 3-speed, “smart” box is Natron, new starter, new batteries, new glow plugs, new glow plug...

...system yourself (instructions are around here somewhere I think) Some threads/pages related to the box https://steelsoldiers.com/threads/pcb-eess-smartstart-s3-i-pics-info.164930/...

Was that a Song Chuan relay that was bad? The reason I ask I have a Nartron box on the bench in pieces awaiting said relay. It appears I will be able to lift the board enough to get to the bottom of the relay on the Nartron.

...the new 50 amp relay for easier replacement if needed. I sealed the hole with a plate and it works as it should. Nice to get the old Nartron EESS out of there, I hated the afterglow on that one. I added a little LED wired to a glow plug so I can see when they are actually on. The S3 box...

Coug is 100%. If glow plugs fried then PCB/EESS box is suspect, and charger getting blamed/framed. YouTube contains a lot of crap too.

...massive reverse EMF from the starter solenoid and arc internally, this for sure has caused the destruction of many starters and very likely some EESS boxes. Even switches that are made for 24V big trucks only control a small relay that is designed to handle the reverse EMF so the key switch...

Ah, ok. So either find another Prestolite box or do a multi-point upgrade to some sort of EESS and a TSU and probably glow plugs as well. I've had this truck for...3-4 years now. It starts like a champ in very cold weather so I don't think the glow plugs are fried, yet.

that box you have is a PCB, it’s got it own dedicated glow plug controller in the water crossover, not a TSU….TSU is only used in EESS series boxes. You are on borrowed time with that old PCB.

Grrr... I went to test everything out and the alternator is working. I'm pretty certain that it's the EESS box now. Obviously, I'll confirm this with the test procedure when it fails again. I have the Presolite box, not Nartron. Black, silver label. My understanding is that Thou Shalt Not Mix...

Hi Mog, yes, the blower motor still works. I've downloaded that troubleshooting guide and I'll report back after I've run through it.

It’s not a signal at the IGN terminal, it’s 24v that is from turning on the ignition to “run”, that comes through the “EESS” box. No 24v? the generator doesn’t know the generator is turning, once it’s turning, it waits to see a stable speed of rotation, this is part of the soft start feature.

...motor is working? The heater gets its power from the same relay that excites the alternator. In any case you also need to check and make sure you have 24V going to the IGN terminal on the regulator. It does sound like a possible EESS box failure. Here is the troubleshooting guide for the alt.

Why do I need to talk about things that are already being inspected/relpaced? Doesn't really seem necessary to discuss everything happening to the truck. Thanks

...no-one does… before talking about fluid changes on hubs, transmission, X-fer case, engine, power steering, brakes, fuel system…and discussing EESS vulnerability, replacing ball joints, control arm bushings, tie rod ends…? Short answer… Leroy is awesome but reconcile that with HummerH1 has...

Read my sig line for DIY PCB/EESS box instructions. Lots of happy rebuilders.

Welcome to the SS forums!! There is little repair info for the EESS boxes as there are so many different ones and they were never meant to be repaired. The burned component is almost never the actual problem so intensive troubleshooting skills are required

Had you re-seated the inside and outside plugs on the EESS box before?

So I modified my eess box with a manual switch and solenoid, when I push the button I get 24v to the glow plugs but when I let off it still has 19v going ro the glow plugs, unless I switch the main switch off then it goes to nothing, anyone have a schematic to make sure I wited it right

My signature line contains a link on how to “restify”, (restore with modifications), PCB/EESS with schematics and explanations. Undertake at your own risk.