Elec power will not trun off

[jasonjc]

I will start with the last time the truck was started. The batts were weak and the truck did not start. So I jump it with the deuce. It started and ran fine. I shut it off just fine then restarted it on its own power just fine. Shut it off again with the start switch. No proplem. Shurt off the battery switch worked like it should. Unhook the jumper between the truck batterys ( jumper cables were removed earlyer) to charge them. They sat for weeks unhooked. I went to start it the other day and all seemed all right. Shut off the start/run switch eng died like it should. Then truned off the battery switch and seen the the red light (brake) stayed on, looked and seen that the gagues and other stuff was still on too. Retryed the switch and still power is still on. Unhooked the jumper (dog bone) and left it for the night. Next time I went to try it , I hooked up the jumper and the air buzz came on, with the power switch off, all the other stuff that should come on with the battery switch was on too. But the switch was still off. I also herd a relay click as soon as the jumper tuched the battery post along with the buzzer going off (on). I thought the switch was bad so I pulled it off and unhooked it. Still all the stuff were on. I put the switch back in and tryed tapping on the control box, thinking the relays were stuck. The only thing that did is seem to keep the start switch from working now. The only way to trun off the power is to unhook the battery. I pulled the box thinking the relay was stuck. I put a omh meter between the two big pins I get nothing like you should.

Now where should I look next?

I see threads with no power, but not power staying on?

 

[73m819]

either the master switch is bad or the power solenoid is stuck

 

[jasonjc]

With the master (battery) switch unpluged it still does it.
The solenoid in the control box? If it was stuck would it not show that when I checked the box on the bench? I was thinking that too.
I have the wiring diagram and I going to try checking the control box some more.

 

[jasonjc]

OK I did some more testing and found that I have the newer better(mya$$) control box with a PCB. So it seems the PCB failed. So when I hook up the battery this thing opens the relay/solenoid. I can bypass the PCB but will lose the starter lock out. Is that all this thing does? It seem you could just use a relay. Why do you need all this other stuff?? In the last two pic's it looks like the small pink looking diode may be bad on the back side of the broad it looks llikes it got hot/brunt? How can you test this stuff?

For now I'm just going to bypass and remove power from the PCB. And hook the solenoid's right to the switches.

Unless some says this will blow up my truck.?.

 

[73m819]

I have been saying for ever why not just eleminate the PCB, wire like a deuce or the older 5ts, the PCB is just for the new troops anyway, if you CANNOT here the 250 running and try to start while running, you have NO buisness in the truck anyway

 

[steelandcanvas]

In the last two pic's it looks like the small pink looking diode may be bad on the back side of the broad it looks llikes it got hot/brunt? How can you test this stuff?

Remove one end of the diode off the PCB and test for continuity in both directions. Open both directions, or closed both directions, no good. Current should only pass in one direction.

Ron, Is that all the box does? It keeps you from trying to start a already running engine?

 

[jasonjc]

I have been saying for ever why not just eleminate the PCB, wire like a deuce or the older 5ts, the PCB is just for the new troops anyway, if you CANNOT here the 250 running and try to start while running, you have NO buisness in the truck anyway

Good, that is what I did. I'm still using the solenoids in the box but not the PCB.

 

[73m819]

If/when I do this, I'll use some BIG solenoid's for the master solenoid like the ones used on the old gasser 5ts, or used on OLDER construction equipment, these are big, can handle a he11 of a load, water proof, last for ever, viberation proof, the contact plates are huge hence low heat built up, thay cost a bit but are worth it

 

[jasonjc]

To bypass the PCB all you need to do is:
1: remove this wire (orange) from the solenoid and cut off the ring and tape the end of the wire.
2: remove this wire (blue) from the solenoid and cut off the ring and tape the end of the wire.
3: cut this wire (black), put a ring connector on it, and put it in place of the blue wrie 2 on the solenoid.
4: cut this wire (red), put a ring connector on it, and put in place of the orange wire 1 on the solenoid.
5: remove this wire (brown) from the solenoid and cut off the ring and tape the end of the wire.

As long as the solenoids are good this will fix you right up.

Too remove the cover , I just held it up in the air by the cover and tap on the base at the seem with a hammer all the way around and got the cover off like that. You also need to remove the 4 screws that hold the plug in.

Hope this helps some one else.

You can get new replacement from Erik's for $140 as of to day.

 

[Beerslayer]

I have been saying for ever why not just eleminate the PCB, wire like a deuce or the older 5ts, the PCB is just for the new troops anyway, if you CANNOT here the 250 running and try to start while running, you have NO buisness in the truck anyway

Great minds think alike. I see you commented in the thread I started here
http://www.steelsoldiers.com/5-ton-...ries-5-ton-eliminate-electronic-controls.html
and I thank you for that. Along those lines, but it is better if we keep that nonsense in the modification and hot rodding side of things or we will get some hackles raised here in the purist side of things.

I would appreciate any help, comments, heckling, whatever you have to add about this subject. As I work my way through the wiring on this fine motor vehicle, I am going to clean it up and streamline things. A few solenoids, push buttons, and we should be set!

Anyone who cannot safely operate one of these trucks without the electronic interlocks, in my opinion should not be behind the wheel of one in the civilian world.

 

[cranetruck]

Control box without the PCB...

 

[steelandcanvas]

As always, very nicely done Bjorn. The photo and schematic will go in my MV Electrical File.

 

[jasonjc]

I got my bypassed box back in today and all works as it should again.

I had a 2 ga jumper between the batterys. Got to thinking that mite be too small so I added a 2nd one today. Boy did that make a difference in starting. So bigger is better in battery cables. And just think it's only 12" long.
So I don't know how those cheap car jumper cable will work on these big trucks.

 

[cranetruck]

Glad you got it done Jason. Often the cables can handle the current, it's the connections that create problems.

 

[Ord22]

Thats awesome work!!