923A1 Trouble After Welding

[DampLemonade]

Hey all,

Bad news. I took my truck to a welder shop to get a trailer hitch receiver put on, as I do not trust the quality of my own welds. I showed them where to disconnect the batteries and where to disconnect the ground strap from the PCB, but alas, the welders did not remove the ground wire from the PCB and now the truck wont start. They also left the battery switch in the ON position while they were removing and reconnecting the batteries.

I do not hear any relays clicking when I engage the starter switch which leads me to believe its the PCB, however the battery disconnect still seems to work okay. I did not have a starter tester or starter jumper on me when I went to pick up the truck today, so I can't say definitively that the PCB is fried at this moment, but before I try and tackle this issue further, is there anything else I should be looking at or considering? Is it most likely the welding fried something in the PCB?

Additionally, the shop wants the truck out as soon as possible since it obviously takes up a bunch of space. Is there a good way to jump the starter on the NHC 250 with it still on the truck? Just so I can get it home? I've jumped plenty of chevy starters with a screwdriver, but thats half the voltage and a tenth of the amperage. I'm assuming I'm gonna have a hard enough time getting them to reimburse me for a new PCB, I don't even wanna imagine the headache of getting them to pay for a tow truck to take it home.

I know it doesn't need to be said but it ran perfect when I drove it in. Woe is me

 

[DeMilitarized]

Hey all,

Bad news. I took my truck to a welder shop to get a trailer hitch receiver put on, as I do not trust the quality of my own welds. I showed them where to disconnect the batteries and where to disconnect the ground strap from the PCB, but alas, the welders did not remove the ground wire from the PCB and now the truck wont start. They also left the battery switch in the ON position while they were removing and reconnecting the batteries.

I do not hear any relays clicking when I engage the starter switch which leads me to believe its the PCB, however the battery disconnect still seems to work okay. I did not have a starter tester or starter jumper on me when I went to pick up the truck today, so I can't say definitively that the PCB is fried at this moment, but before I try and tackle this issue further, is there anything else I should be looking at or considering? Is it most likely the welding fried something in the PCB?

Additionally, the shop wants the truck out as soon as possible since it obviously takes up a bunch of space. Is there a good way to jump the starter on the NHC 250 with it still on the truck? Just so I can get it home? I've jumped plenty of chevy starters with a screwdriver, but thats half the voltage and a tenth of the amperage. I'm assuming I'm gonna have a hard enough time getting them to reimburse me for a new PCB, I don't even wanna imagine the headache of getting them to pay for a tow truck to take it home.

I know it doesn't need to be said but it ran perfect when I drove it in. Woe is me

Take the screw plug off the bottom of the PCB and jump the two big connectors on the pigtail. Should allow the truck to start as normal.

 

[DampLemonade]

Take the screw plug off the bottom of the PCB and jump the two big connectors on the pigtail. Should allow the truck to start as normal.

If i have the PCB connector off, won't that not allow the battery master to come on?

 

[DeMilitarized]

If i have the PCB connector off, won't that not allow the battery master to come on?

Your jumping the wire

 

[87cr250r]

Have you verified that the battery is not dead? Frying ECM's with a welder is urban legend. How do service trucks survive?

 

[Jbulach]

If your battery switch is still functioning, jumping the big C&D terminal is not going to help, as that is essentially what the battery switch does. Try screwing the fuel shut off in, flipping the battery switch on, start switch to run, then jump the small trigger wire (#74 iirc?) terminal and the big positive (wire #6) terminal on the starter solenoid to crank.

 

[Jbulach]

Have you verified that the battery is not dead? Frying ECM's with a welder is urban legend. How do service trucks survive?

They most likely blew the diode on the top (start) solenoid in the pcb while monkeying with batteries or reconnecting them wrong with the switches on. Never let a shop unfamiliar with these trucks operate them or touch the electrical system.

 

[Elk1111]

It never hurts to at least try banging on the PCB box a few times with a light hammer first before you try jumping anything. Sometimes it works sometimes it doesn’t.

 

[DampLemonade]

Have you verified that the battery is not dead? Frying ECM's with a welder is urban legend. How do service trucks survive?

the batteries are fully charged

They most likely blew the diode on the top (start) solenoid in the pcb while monkeying with batteries or reconnecting them wrong with the switches on. Never let a shop unfamiliar with these trucks operate them or touch the electrical system.

i think this is most likely. I got a chance to talk to the owner of the shop today. He said he personally removed the battery cables and PCB ground wire before welding but was not around when his guys put it back together and tried starting it.

He was apologetic and is paying for a new PCB, so there is a silver lining here. Today or tomorrow I should be able to go up to the shop and try to jump the starter solenoid to get it home. Thanks for all the pointers guys, I appreciate it

 

[TechnoWeenie]

Gotta love shops.

'We screwed up your truck, hurry up and get it out of here'...

They're paying for repairs, right? RIGHT?!

 

[DampLemonade]

Gotta love shops.

'We screwed up your truck, hurry up and get it out of here'...

They're paying for repairs, right? RIGHT?!

I did my best to not burn any bridges since the owner seemed like an honest enough guy once I was able to talk to him directly and not one of his shop workers. I told him it was a fairly simple part to replace so I just had him subtract the cost of a new PCB from the job and we were square. I threw the new box in there and its back to normal now.

When I bonked the old box with a rubber mallet it has about a 45% good start rate which I thought was funny. Planning on opening it up and trying to fix whatever blew, just so I can have a spare on hand