Ways To Fry PCM or Electronics Discussion from FB

R Q

R Q

Well-Known Member
Joined
Apr 4, 2005
Location
Charlotte
On one of my FB groups

I See You Dont Know Shit About Welding​

there came up a discussion where a guy was welding on a logging boom truck and a day after he was done the ECM died and he was blamed. Operator had cut off the battery kill switch and they started the machine afterwards and it ran but there's a lot of points in the discussion that I had not heard of such as unplugging ECM and any electronics whenever doing any welding and several other points. It's a pretty good thread. I know I've welded on my rig without disconnecting the battery by mistake but now I'm thinking maybe I should disconnect the ECM
Sorry this post is such a cluster, I just can't get it right.
 
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FB Didnt load, here's the original text from OP "
Let's debate. I'd like to hear from those with actual experience and not what you heard.
So I got a call out to repair a headache rack on a piece of logging equipment. When I arrived the operator told me he had switched off the battery disconnect. I straightened the rack and welded some new supports in place. I ground a clean spot for the ground right on the rack and did all the welding needed. After I was was finished we flipped the battery disconnect back on and fired up the machine to move it out of the way. The next day they used it for a few hours. This morning it wouldn't start and threw a "No ECM" code. They called local John deere dealer and they immediately said it was because of the welding without unhooking the batteries at the battery. Has anyone ever heard of something like this? I know a bad ground or welding on opposite ends of the ground and all the other horror stories about burning up the ECM. But in this case we flipped the disconnect switch, clean ground close to welding area and the machine was used for a couple days before the issue. Let's argue, I mean debate. Lol"
Generator Rentals
Yes it happens very very often.
Probably has a killswitch due to parasitic electric draw.
The welding current went thru the parasitic draw and fried the computer.
I bought a product called “anti zap” works the balls.
Just hooks onto the battery and it’s ready to weld no disassembly of anything required.
Product is about the size of a fat calculator




Kyle Ransom
Generator Rentals anti zap will only protect the battery, should have the ecm unplugged



Benjamin Harris
Kyle, no, antizap protects the ECM as well. I used to build dump trucks. Had several guys fry ECMs because they “forgot” to disconnect the batteries. They gave every bay an AntiZap and we didn’t have another one fry.

Benjamin Harris
If the welding had hurt the ECU, it would’ve shown up immediately. I’ve NEVER seen one get hurt by welding and not show up immediately.


Kyle Ransom
Benjamin Harris I work at a truck mounted equipment dealer and they've had problems on gm's, fords and dodges even with an anti zap on each battery, the dealerships want all battery terminals off, ecm unplugged and body control module unplugged. The body control module will actually record abnormal voltage spikes. An anti zap will just absorb a voltage spike at the battery, nothing more


Jeremy Morgan
Benjamin Harris I’ve seen only one that took one start cycle to fry.
 
Maybe I am not thinking about this correctly, but if you disconnect the battery, the circuit for the ECM should be broken. I would think the welder would need to complete the circuit to fry the ECM. Now if the welder is close enough to generate an EMP/RF type signal, maybe that could fry part of the board?
 
I actually was thinking about this exact topic last night as I welded on the rear axle of my jeep. I'm no electrical engineer, but the clear path for electron travel to the ECM just doesn't show itself to me. Maybe like @paradisePWoffrd said, there's some situation where some type of waveform could cause a problem, but that would not be from the short-circuit welding side of things.
 
So if this is a thing (frying electronics) how do people get away with running power pack welders off of their running vehicles doing trail repairs?
 
I work for a equipment manufacture, it calls out in the manual for every machine. disconnect battery, ECU, ACU, Plus-1 and all expansion modules and MURR blocks.

I fried the alt. in my jeep welding a mount on the exhaust with the ground with in 3" of where I was welding. I disconnect everything.
 
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