Laying out a brace strut in my mind for my car and just keep thinking about this. With all the elctronics in the car (AEM wideband, fuel pump, electric fuel pressure gauge, etc), I keep wondering about grounding on the car. Even with the battery unhooked from the car, can it still run in on something and do some damage?

 

I've never heard a good answer on this, but I've never had a prob welding on my cars or trucks... so far And, I never unhook the battery.

 

Ditto.

I've read before that you should just unhook your battery. I've also read that you should unhook your battery and unplug your ECU. And I've also read that you should unhook your battery, unplug your ECU, and do a voodoo dance first. Then I read the above where someone hasn't unplugged anything and welded on their car and didn't have a problem.

In most instances I think if your ground clamp is very close to your weld you should be fine, the current is going to take the path of least resistance. Generally your ground cable is very big and less resistant than everything else. Now in your case, in order to be safe, I would unplug the ECU at least. It should only take a little while and would help save your expensive computer for sure.

 

I have a little yellow box thing that you connect to the battery, don't know what it does exactly but i've never disconnected anything.

 

i think it was brian from B&G said he once had a problem with the bearings in an engine fusing together while welding on a car

 

so unhook the battery, unplug the ecu, do a dance, and pull ur motor

 

Lol, or find some big grade 8 bolts to use. Makes me nervous.

 

Unhook the ecu and disconnect the battery. When we were welding on a friens limited street car we use to always take the FAST box out of the car and disconnect the battery. I have heard of people ruining FAST boxes leaving them hooked up. I would unhook it for saftey, but thats just me. Good luck

 

Ive heard a couple storys about DFI and FAST ecus along with some msd type setups getting fried during tig welding...

 

I've never had a problem myself but you do want a GOOD CLEAN ground close to or on the same structure thats getting welded. Of course I may have just been lucky everytime.

 

Last time I was TIG welding on a car, I touched the chassis, and got the local oldies station play'n in my head.... hmmmm

 

yep! had that happen once or twice. yeha just unhook your battery.

 

:withu: Disconnecting the gound wires on sensitive equipment is always a good idea, and cheap insurance.

Also, when welding on assembled rearend housings, make sure to have the ground clamp on the same side of the axle housing you are welding on. You can arc through the bearings and ruin them in short order.

 

What I don't get is how does unhooking the battery help?I would think it would work like a buffer and absorb a voltage spike. And as far as msd failing after welding, well they fail 2 and 3 times during 1 nascar race, but that is another story. i have also seen devices that you can hook up to the battery to stop electronic frying when welding, but it is probably just a scam too.

 

Did he ground the welder to the flywheel??? I don't believe that at all. I can see problem in the rear housing, that makes sense, but not the engine bearings/

 

Now I can tell you one thing to watch for. And that is High Freq TIG operating garage door openers! I was in the trunk of a car all contorted and I started the pedal and had my garage door open. I thought it was the Wife and was pissed at her for not shutting it. Then after alittle while it did it again. Then I figured it out and it got to be fun to play with trying to control the garage door. My opener has one of those rolling code deals, so I dont know if thats why or if it was due to the reason they put all the pics in the TIG's installation manual about grounding the hell out of everything in the area of high frequency TIG.

 

I know tie a ground wire around my...well you know... when I'm TIG welding to try to keep the oldies from playing in my head...

I guess my high freq is right around 94.9 Mhz.....LOL

 

I watched, and yes it happened, but it was arc welding not tigging.

 

Wow, good chat on this one, I am using a Mig, easy enough to unhook everything, just a reoccuring thought I have. The grounding close to what you are welding is a safe measure for the path, just never know where electricity can go.

 

I just unhook the battery and unground the msd and 2step. So far so good and we've done a cage,subframe connecters, and turbo kit...we also have debated this in the garage...