Search results for query: eess

...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.

...connection is tight. I have seen them come free, including on my rig. Check and clean all battery connections too (you implied you did that). Also, unlikely but still ensure both PCB/EESS plugs are on tight. [EDIT- RWH’s post directly below mine is probably the best diagnosis. Failed regulator]

That's a diode. I read someone's post about that and they said it was 1.5 amp but I don't know about the voltage rating. I'll try to post the link to a good discussion on these boxes. https://www.steelsoldiers.com/threads/pcb-eess-smartstart-s3-i-pics-info.164930/ Good luck.

My bad. I was using old terminology. Box is of the "smart" generation. I will test plugs and try a different box. I, too, thought 15-20 seconds was too long.

...different like 0000 or no reading...then there toast. If toast then your box fried them . If you have a PCB box....those are real old and have been updated to EESS, and then to S3 smart start. The last two use a TSU controller in water crossover. 15-20 seconds power to plugs is to long a time.

White smoke is not necessarily over fueling, it is unburned fuel as there is a difference, your glow plugs/EESS are likely at fault. You also need a good set of batteries especially when it is cold.

...starting this truck beginning in late November - early December. It has a new GPC, new glow plugs, and what appears to be a functioning PCB EESS/S3. The batteries were reading 24+ volts, but they were depleted a bit with all the engine cranking. They're currently charged up. The PCB...