No power on m923

[Cobra2401]

I need some thought/advice. I have a m923. Was driving it, all the sudden it died, everything died. I smelled something melt or burn for a few seconds- thinking it was coming from the dash area? To get it home I bypassed the electric fuel pump by turning that thumb screw on the injector pump and jumping the starter. I thought it was that "black brain box". Not sure what you call it. The box that sits right behind the washer fluid bottle. I had a spare one of those boxes so I changed it out. Still nothing. All the lights works. But none of the dash electrical gauges work nor does the start switch. You can hear the battery selinode kick on when you turn the battery's on. I checked to see if I have 24v. I have that. I was gonna check the starter switch. Maybe that.? But wouldn't I still have power to the gauge on the dash if that switch wasn't working. Any help thanks

 

[Suprman]

If you smelled something melted and burnt chances are something melted and is burnt. I would check the alternator and all the wiring to make sure it didn't rub thru somewhere and you have a short. You bypassed the fuel solenoid by turning the knob screw by the pump. It is possible that the pcb is bad but if it were me I would be searching for the source of the burning smell and go from there.

 

[Cobra2401]

What's the pcb? I checked the alternator. I just had it rebuilt during the winter. That's working. Yeah, I'm gonna take the dash off and see if I can find anything. I was just wondering if anyone has run into the same scenario as me. Or similar? To help narrow things down..... Lots of wiring to go through if I don't have an idea?

 

[Suprman]

Pcb is the black box thing on the firewall behind the washer fluid bottle. Download the p2p wiring guide

 

[Cobra2401]

I have a spare pcb box that I switched out. It still didn't work.

 

[Coffey1]

I would look at the start switch and all wires going to it.

 

[Cobra2401]

Yeah, I'm gonna take a look at that today. After work. I hope it's not to hard to trace down ? Thanks for the info. I really appreciate it

 

[av8or]

If the switch checks ok, I'd look again at the pcb, test it to make sure both solenoids are working.

 

[doghead]

If your alt went out before, maybe you have a bad battery or connection(short).

I would not rule out the alternator just because you fixed it recently. If you did not fix whatever caused it to go bad the first time, I would expect the same to happen again(this time).

The -20/24 level TM should have easy step by step troubleshooting procedures to follow for such an issue.

 

[Cobra2401]

The dash lights come on and all the driving/marker lights go on. Just the electrical gauges don't work. I took a look at the wires today. Haven't found anything melted yet. Is there a way to test the pcb to make sure it's working!

 

[Cobra2401]

The battery switch selinode kicks on but still nothing when you try to start it

 

[fuzzytoaster]

Was there any update on the solution for this?

 

[jonsm114]

Make sure the control box connector has full contact.......clean and lubricate with silicone grease. Just had that problem myself.....no start, pulled plug and removed box...opened and took a look. Reinstalled box on firewall. As I was screwing plug back in place I felt solenoid click and heard valves spooling under chassis..I stopped and realized the ignition switch was still left in on position. All gauges were up, hit starter switch and she fired up. I let it run a bit......and shut down. Returned to control box and tightened plug. Went to start and same problem. no start. Left power switch on and was backing off plug again then same thing, click and spool up...I realized it was the plug..itself. Cleaned and reinstalled, not working fine.....loose pin? Dirt? Who knows.

 

[fuzzytoaster]

I'm having two trucks do this to me currently, one has power to the gauges and the other doesn't. I installed a known good box to simplify the situation but still no-start. I've tried the percussion maintenance, cleaned the contacts, and checked voltages to the bendix and starter it self..all a green for go. I'll fiddle with the PCB connector some more.

 

[fuzzytoaster]

Update:

I bypassed the PCB box with jumper wires and still nothing from the starter. I'm having a shop take it out and see what the deal is, hopefully just a bad unit. I'm fearful of the engine being locked up but even if so the starter would try to do something.

 

[Artisan]

I am not saying the below IS your issue butsomehowever;

ALL A0/A1 5 TONS HAVE A VERY BAD HABIT OF THE MAIN BATTERY CABLES
RUBBING ON THE DS REAR CORNER OF THE ENGINE. NO MATTER WHAT
YOU DO, YOU CAN NOT SEE THAT AREA. ALLS YOU CAN DO IS DISCONECT
THE WIRES AT THE STARTER AND BATTERYS AND PULL THEM TILL YOU
CAN FOR SURE SEE EVERY LAST INCH OF WIRE AND IT IS NOT EASY TO DO.
A QUICK FIX ONCE YOU FIND THIS INHERIANT TRAIT IS TO PUT RUBBER DISHWASHER
HOSE OVER THE CABLES DOWN TO WHERE THE INSULATION IS WORN OFF.
IT WILL HELP FOR A SHORT WHILE.

THIS SHOULD BE A STICKY. Been there done that, seen that and
suggested the sticky many times. Few follow thru and investigate
to the extent that is necessary because it is very time consuming
out of sight = out of mind . PUNT.

 

[gem1410]

Anyone find out the cause of engine running but no gauges or heater motor operating--thanks George

 

[WillWagner]

Anyone find out the cause of engine running but no gauges or heater motor operating--thanks George

Instead of piggybacking an OLD thread that has nada to do with your issue, maybe start a new one with your question. You are more likely to get some responses in regards to your issue that way.