Ever see inside the Protective Control Box?

[Dan Neubert]

They are 48v diodes. You do not need them. They only for in case you hook the batteries up backwards.

Cole Harsee 24063 is the solenoid numbers.

Thanks for the help.

 

[freedom ridge]

Does anyone know where this broken wire goes to from the PCB?

 

[simp5782]

Does anyone know where this broken wire goes to from the PCB?View attachment 751203View attachment 751204

The far left? With The diode? To ground. You do not need it

 

[freedom ridge]

So just hook it up to a ground? Which ground? I can just replace with a wire?

 

[simp5782]

So just hook it up to a ground? Which ground? I can just replace with a wire?

No it is a diode. It hooks to the rivet that holds that solenoid to the box just below it. Basically from that big terminal with the yellow ring terminal to the ground on the rivet at the box.

If you want to burn your wire harness and truck to the ground go ahead and replace it with a wire. If you don't understand diodes and their function. Do some research before you go hooking wires anywhere and everywhere.

The diode simply shorts to ground in the event that the diode sees 48volts or more. or from hooking the batteries up backwards. You do not need it. If your PCB box was bad due to no start condition and your ABS was working correctly. Then just replace the lower solenoid in the box. Cole Harsee 24063 or some other 24v variant 600amp cont. solenoid.

If you don't understand it then I can sell you a rebuilt and resealed box for $130 and you send me your old box back. I will include the return shipping label.

 

[freedom ridge]

So the fact that it is burnt up and not connected will not cause any issues, but if I was having issues, I probably have another issue in the box? Because I had no continuity when I was doing the checks in the TM. The TM had multiple tests that lead to "REPLACE PCB". So I took it out. No crank, no power anywhere really. Battery switch and ignition switch was working and had power to the PCB. Neutral safety switch is working and tried wiggling the shifter. Batteries tested good and are not even old. What cause the issue was the generator went out and overcharged the system. Issues occurred after this. Had it rebuilt and was working properly. Tried disconnecting the starter lockout signal wire too, as it said in the testing, which did not do anything. Guess I should test the solenoids?

 

[simp5782]

So the fact that it is burnt up and not connected will not cause any issues, but if I was having issues, I probably have another issue in the box? Because I had no continuity when I was doing the checks in the TM. The TM had multiple tests that lead to "REPLACE PCB". So I took it out. No crank, no power anywhere really. Battery switch and ignition switch was working and had power to the PCB. Neutral safety switch is working and tried wiggling the shifter. Batteries tested good and are not even old. What cause the issue was the generator went out and overcharged the system. Issues occurred after this. Had it rebuilt and was working properly. Tried disconnecting the starter lockout signal wire too, as it said in the testing, which did not do anything. Guess I should test the solenoids?

The blown diode protected the abs solenoid and the abs module. That is the top Solenoid. The lower solenoid is what runs the truck. It is blown more than likely causing your no start condition

 

[freedom ridge]

So I can just remove that blown diode and not worry about replacing from what I understand, correct? And then I will test that bottom solenoid. I can manage that. Thanks

 

[simp5782]

Yes. Replace both solenoids if you are going to be in there though and just test your upper and keep it for a spare. If you are in there you might as well replace everything and be done with it rather than a week from now the solenoid going out from unknown reasons

 

[simp5782]

Will bump this with a work around to a single solenoid setup. This will delete the upper solenoid that runs the starter connection in the PCB. You simply unhook the power supply wire (black) from the solenoid on top and the bottom and discard it. Remove the small green wire to the solenoid, remove the white power signal wire from the opposite side of the solenoid and hook the green wire to the white wire with a butt connector. The green wire isnt very thick so it can't take long cranks I wouldn't believe so I recommend just replacing the whole start signal wire

Another delete is to run a wire from the starter solenoid. Up the harness and into the dash and plug it into the appropriate connector on the starter switch in the dash. Use. 12 or 14gauge wire for this.

You can always rebuild your box with 2 continous duty 24063 solenoids and leave the upper one in there as a spare in the event your box goes out on the road. You could swap the solenoids around with simple hand tools.

https://youtu.be/RKlRtqTanaM

 

[74M35A2]

Best to only delete the PCB starter solenoid if you have upgraded to a modern starter which contains an external relay upon itself, pictured below. Dash starter switches are typically not rated for starter solenoid power. They can and will do it, but question would become for how long.

I did make make an emergency PCB jumper plug from an old PCB box, which allows dash power to be restored, and can then just jump the starter at the starter to crank the engine.

 

[Wayne from Maine]

I would like to know if the original post with the new style PCB has been fixed with a workaround or parts numbers. My box failed, luckly I have a second truck to borrow from and am still able to work. There is plenty of info on the older style. I ordered 4 cole-hearsy relay's and opened my box to discover a completly different animal. Any info would be appreciated. Wayne

 

[simp5782]

I would like to know if the original post with the new style PCB has been fixed with a workaround or parts numbers. My box failed, luckly I have a second truck to borrow from and am still able to work. There is plenty of info on the older style. I ordered 4 cole-hearsy relay's and opened my box to discover a completly different animal. Any info would be appreciated. Wayne

Post a picture of what the inside of your box looks like and we can better help you...

There are 2 different types of 939 series box . One is the two solenoid and one has the circuit board in it. Basically the circuit board just takes the place of the original diodes the first generation box had. And you do not really need the diodes at all. Unless you plan on hooking the batteries up backwards.

 

[Wayne from Maine]

View attachment 771677

This is my control box. There is no apparent sign of any damage to the wiring or connections. I expected to replace the relays with the cole-hearsee ones.I even ordered 4 so as to change the second truck which does not have an issue yet.

I have not seen any comments regarding this set-up.
I would be happy to eliminate the whole protection stuff if thats possible.

 

[simp5782]

View attachment 771677

This is my control box. There is no apparent sign of any damage to the wiring or connections. I expected to replace the relays with the cole-hearsee ones.I even ordered 4 so as to change the second truck which does not have an issue yet.

I have not seen any comments regarding this set-up.
I would be happy to eliminate the whole protection stuff if thats possible.

Your picture did not post

Or text a pic to 901 318 8353

 

[frank8003]

I am just imagining...............
But after reading everything posted on SS about electronic boxes built into 5 tons and (AFTER THE DEUCE) and other vehicles and Our tanks, guns , ships, subs, and aircraft of all flavors, I see that the JLTV series is gonnah be another can of worms.

 

[Wayne from Maine]

clicking on the attachment number it pops upon my screen. must have done something wrong first time picture and struggled with trying to get it to work

 

[simp5782]

It is basically the same box listed in post #1

 

[Wayne from Maine]

I saw that and was looking for the follow up dicussion, but the forum headed off with older style and never came back to post #1 box. Thanks for your help with my mongrol...

 

[Thomas18Z]

Here's the inside of my PCB:
View attachment 536582

Have we established a way of getting rid of the circuit board? I've seen some very clean looking boxes with just the two solenoids and a couple of diodes attached to them.
With my truck, the main power switch would activate the one solenoid just fine, but the run switch activated solenoid wouldn't work. Tap on the PCB box with a hammer and it would come to life. So I figured since I've got the box open, I'll just replace both solenoids and if possible dump the circuit board in order to simplify things in there.
I went to NAPA for the solenoids, but they are a bunch of incompetent stupid people in there. They can't find parts like the older guys could. They rely on the computer and demand you tell them what make and model vehicle it is for. After explaining to them that their computer system isn't going to have a 5 ton military truck listed, they just tell you that they won't have it.

Any insight?

So is there some info on eliminating that circuit board? It seems like the thread never really ends up addressing that question specifically?