Welding and Electrical Concerns

Wanted to see if I could get some comments on whether welding can cause electrical issues if you do not disconnect your battery first???

 

If you do a google search, it is generally recommended that the battery be disconnected before welding. Some even advise disconnecting the ECU.
Seems like a no brainer - better safe than sorry.

 

Better safe the sorry always disconnect the negative cable .

What can happen is you can have welding current flowing all through the vehicles electrical system .

There are some that will say you will not have any issues.

Having to buy just one Computer was enough to always remove the negative battery terminal

I had a friend that was some what lucky in his case if caused every light bulb in the vehicle to just melt the filaments far cheaper then the ECU

 

The only way that it can cause any issues, is if you hook up your welder cables incorrectly.

Electricity follows the path of least resistance. ONLY. It CAN NOT flow through "all of your vehicle's electrical systems" unless you hook the cable up to place all of those systems INTO the circuit you are making with the welder.

Always do your welding close to the ground clamp, and onto the SAME piece of metal to which the ground clamp is attached.

 

Yes, still a good idea to unhook at least the negative also. I'm worlds worst about wanting to do it and having to reset, relearn radios and tunes but it really is a good idea.

 

I will call you on the current not being able to flow through the vehicles complete Electrical system .

If you fail ***to remove the the negative battery cable !!

Simple to check just see how many places you can measure OCV .

So just which way should the cables be hooked up ??

Some use self Shielded wire Last I looked that was straight polarity

Some Run Hard wire That is Reverse polarity .

In each case your work cable is different

So which is correct ??

 

That is about as close to indecipherable as anything...

And also note something about polarity; it is IRRELEVANT unless the vehicle's ELECTRIC system shares a common reference voltage with the electric power grid to which you attach the welder. So thank you very much for giving me the prompt to come up with this meaningful insight!

In other words, you would have to do something really stupid, like weld on it WHILE YOU HAVE A BATTERY CHARGER HOOKED UP TO THE BATTERY, or a block heater that is plugged in, or something like that.

If you have a wire feed / mig welder hooked up in REVERSE POLARITY, while the vehicle is connected to a battery charger or plugged into a block heater, then if you so much as TOUCH the ground clamp to the chassis, sparks will fly.

You can hook the ground clamp of an A/C ARC welder up to the chassis while a battery charger or block heater is connected, but probably not a good idea to actually weld.


I wonder if that is where the whole "unplug the battery" paranoia originated? Somebody tried welding on a vehicle while it was otherwise plugged into the power grid, and sparks flew?

If you're welding on a vehicle, the welder cables should be the ONLY connection between the vehicle and the power grid. NOTHING ELSE.

 

He's prob. right. I've never had an issue and remember I'm worlds worst about following my own advise.