Welding without frying

[firemanmike69]

I still don't see how disconnecting the batt isolates the PCM from the welding voltage??? It disconnects it from the batteries 12v, but the PCM still has wires hooked to the chassis and various other sensors that may be conducting the welding voltage

Just did some welding on a brand new paver at work with the factory rep from Sweden, his words were " when you weld on my machine you will disconnect battery shut off switch and remove harness from machine controller" that would eliminate any way that stray voltage could find the control computer and damage it. On the other hand on our other equipment it is also the manufacturers recommendation that the controllers be separately unhooked and we never do that, just unhook the batteries and weld away with no problem

 

[IslandTractor]

My son is taking an auto body class at a tech school. They give three welding classes oxygen/acetylene, ARC, and MIG. The instructor said there will not be a TIG class because of the electronics on all of the new cars today. So I am assuming the high frequency will damage the newer cars electronics. Wether that is fact or just their opinion I do not know.

I don't know about high frequency starts but the basic TIG welding process is no different than any other arc weld with regard to how electric current flows. Why would lift or scratch start TIG differ at all from SMAW with regard to car electronics?

 

[Shield Arc]

Only reason I'm curious about high frequency on a vehicle, I have an aluminum flatbed on my 2007 truck. So far I have not damaged it, but it is a matter of time! Also been thinking of ways to build a lumber rack for it, but haven't come up with a design yet. I can always take the bed off, but that would be a lot of work, truly would be the safest way to go.

 

[LD1]

Unplugging the harness from the controller (pcm) makes sense. That would isolate it for sure. But simple unhooking the battery to prevent damage to the computer has me baffled??

But also keep in mind that most modern cars have more than one computer. Most also have a BCM (body control module) that would also need unplugged if you are that concerned with it.