I realize this is an old post and may not have any interest to anyone anymore but I'll throw my experience in here anyway. I have never disconnected a battery to weld on a vehicle. I have never witnessed a vehicle being damaged by welding with the battery connected. I have welded on vehicles hundreds of times with absolutely no issues. I've welded everything from frames, body, exhaust, engines ( to remove broken exhaust manifold bolts ). I've used both MIG welders and TIG welders on vehicles, again without any issues. If I think of it, the next time I weld I will hook up my scope and measure the current in the negative cable to the battery and I will also scope for voltage spikes. And, if I think of it, I'll post my results here.
EricGoodrich wrote: I realize this is an old post and may not have any interest to anyone anymore but I'll throw my experience in here anyway. I have never disconnected a battery to weld on a vehicle. I have never witnessed a vehicle being damaged by welding with the battery connected. I have welded on vehicles hundreds of times with absolutely no issues. I've welded everything from frames, body, exhaust, engines ( to remove broken exhaust manifold bolts ). I've used both MIG welders and TIG welders on vehicles, again without any issues. If I think of it, the next time I weld I will hook up my scope and measure the current in the negative cable to the battery and I will also scope for voltage spikes. And, if I think of it, I'll post my results here.
Oh no I'm still interested! It would be great to post the captures of your scope so we have some more insight on the subject.
We do a lot of welding on our fleet equipment (Municipal Government repair shop) and we do a tad more than just disconnecting the battery in some cases ( Fire Trucks with Multiplexing systems). A few times, our techs forgot to disconnect the ABS modules before welding on trailers and we did fry two of them.
Just as an example of the procedure Ford recommends.
Did some exhaust welding today. Standard MIG welder. Battery connected. Blue channel is an inductive amp clamp around the battery cable. Red channel is voltage across the battery terminals.
The three second Mark is when I began welding. The seven second Mark is when I stopped.
I apologize for not providing pictures of waveform zoomed in, honestly there was nothing to see anyway.
EricGoodrich wrote: Did some exhaust welding today. Standard MIG welder. Battery connected. Blue channel is an inductive amp clamp around the battery cable. Red channel is voltage across the battery terminals.
The three second Mark is when I began welding. The seven second Mark is when I stopped.
I apologize for not providing pictures of waveform zoomed in, honestly there was nothing to see anyway.
YES. This is exactly what I've been meaning to do! Many thanks sir, much appreciated.
Still, it's really interesting that Ford wants you to be super careful when welding on their trucks. :blink:
Denisf wrote: We do a lot of welding on our fleet equipment (Municipal Government repair shop) and we do a tad more than just disconnecting the battery in some cases ( Fire Trucks with Multiplexing systems). A few times, our techs forgot to disconnect the ABS modules before welding on trailers and we did fry two of them.
Just as an example of the procedure Ford recommends.
Welding Precautions
Here I was thinking I was overly cautious when disconnecting the battery. :silly:
Last summer there was a guy over at my house grinding a few stumps and noticed I had a welder out by my car with the hood open. He came over and told me that among many things, he was a "master welder" and to always disconnect the neg cable because he was doing some work on a car when he started out and cooked the rod bearings...we left it at that.
Tutti57 wrote: Last summer there was a guy over at my house grinding a few stumps and noticed I had a welder out by my car with the hood open. He came over and told me that among many things, he was a "master welder" and to always disconnect the neg cable because he was doing some work on a car when he started out and cooked the rod bearings...we left it at that.
I disagree with the article a bit. I have never disconnected the battery before welding and i'll tell you why. This is my theory, electricity takes the path of least resistance, I ground the welder directly to the metal I am welding. If I am welding the exhaust, I am not putting my ground cable to the frame as this will require the high voltage to travel much longer distance not only possibly creating a bad weld but possibly traveling through other components as well. If I am welding on the frame, my ground cable is attached to the frame I am working on, its not being attached to the axle, fender, exhaust, battery, PCM, dash board, etc... The electrons will not flow through anything other component. Why would it? I don't see a problem at all as long as you use your thinking cap and ground to the area your welding.
Tutti57 wrote: Last summer there was a guy over at my house grinding a few stumps and noticed I had a welder out by my car with the hood open. He came over and told me that among many things, he was a "master welder" and to always disconnect the neg cable because he was doing some work on a car when he started out and cooked the rod bearings...we left it at that.
Really? :huh: That's a new one on me...
A friend of mine said he disconnects the battery cause the electricity traveled through the wheel bearing and welded it....I wonder where he was grounding! On the hub? Proper ground location should prevent mistakes like this.
I can argue this further, Ignition coils...Those can blast 50,000 volts into the cars chassis. Why doesn't that effect the car electronics? Because its going directly to ground, proper ground location. You don't see the spark plug grounding through the PCM. lol.
Tutti57 wrote: Last summer there was a guy over at my house grinding a few stumps and noticed I had a welder out by my car with the hood open. He came over and told me that among many things, he was a "master welder" and to always disconnect the neg cable because he was doing some work on a car when he started out and cooked the rod bearings...we left it at that.
Really? :huh: That's a new one on me...
A friend of mine said he disconnects the battery cause the electricity traveled through the wheel bearing and welded it....I wonder where he was grounding! On the hub? Proper ground location should prevent mistakes like this.
I can argue this further, Ignition coils...Those can blast 50,000 volts into the cars chassis. Why doesn't that effect the car electronics? Because its going directly to ground, proper ground location. You don't see the spark plug grounding through the PCM. lol.
I agree with your logic here. I think these other guys and their bearing stories were more likely already bad or nearing bad before the welder came out. Then talking it out loud lead to someone blaming the welder for the failure.
Tutti57 wrote: Last summer there was a guy over at my house grinding a few stumps and noticed I had a welder out by my car with the hood open. He came over and told me that among many things, he was a "master welder" and to always disconnect the neg cable because he was doing some work on a car when he started out and cooked the rod bearings...we left it at that.
Many thanks sir, much appreciated.
