tig welding on cars that have computers

[metalmeltr]

I have been told that TIG welding on cars that have computers can damage the computers. Why is this? With steel you would be running DC so what would cause the damage?

[Desertrider33]

If you use high frequency start, I suppose it could damage the computer, or if welding aluminum in ac with high frequency.

[eyesolator]

I would agree, if there is a problem it would probably with the high frequency although I have never heard of it causing problems? The biggest thing with welding on cars is grounding the actual area/part of the car you are welding so the current is not running all over the place (like through wiring or computers) to get to the weld. And it’s not a bad idea to disconnect the battery too.

John

[Desertrider33]

That's a good point about setting the ground as close to the work as possible. Also don't want to set the ground on the other side of a bearing with the current going through the bearing.

[Sberry]

I dont see how disconnecting a battery helps, I never do it, welded on hundreds maybe more cars, trucks, about anything else that moves, I was going to say besides airplanes but actually did a couple things to one.

[Sonora Iron]

I think every up fit manual I’ve ever read says disconnect the batteries before welding. Some even say unplug the computer.
I have always felt it’s good practice to keep the ground close to your work.

[Sberry]

Keeping the ground near the work is obviously the number 1 thing. I think every technical writer throws the battery issue in just for sport. We have had some lengthy discussions here and only one position I ever heard makes much sense but even that was speculation. No one ever gives reasons why in the recommendation and I know many equipment types, installers never disconnect. I have never had an issue, cant recall where anyone I personally know has either. Have heard some stories, even one where the guy insists he "blew every light bulb out of the car" ha.
Grounding locally is the deal, new cars have so many potential ground loops due to ground wires in harnesses that never used to be there, ground to the part being worked on.

[eyesolator]

I was at work one day and one of the guys had just had a battery stolen out of his car so he decides to weld a chain on the hood, down to the bumper. Car was a piece of crap as you might imagine. So we're sitting in the lunch room and BOOM the guy's battery blows! The current found it's way through the battery and apparently didn't like that 200 amp quick charge.
So you may want to disconnect the battery just in case the current finds it's way through the battery, which is unlikely but better safe than sorry.

[c wagner]

Did he have ground hooked up to the tailpipe?
Was the replacement battery new? (Why bother with a new battery in a junk car?)

[eyesolator]

He had it grounder to the bumper and when he welded chain there it was fine but when he welded a piece of chain to the hood that’s when it blew. Good thing the hood was closed! Yes it was a new battery, that’s what we all got a kick out of. Poor guy didn’t have two nickels to rub together X-wife or two, couple of kids. He lived in the bar and slept in an apartment on the wrong side of town, always broke.