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Disconnect battery for stud gun use?

#1
Have not worked on a new car in a long time. We used to disconnect the battery when welding on a body or frame repair to protect the electrical stuff but these new cars are much more heavily burdened with all sorts of high tech gizmos and ying yang. Got a 2018 Chevy Equinox in the shop needing a liftgate repair that will require using a stud gun. Do I need to disconnect the battery before using the stud gun on this vehicle? Thanks
 
#3
Not being a paint guy but more of a mechanical guy, with the sensitive electronics in cars these days, I disconnect the battery for almost anything more complicated than an oil change, especially if it involves sending current through the metal of the car, like a welder or stud gun will. Just remember that if you do this, some vehicles have security features that require putting in codes after you power stuff back up. You can usually find that in the owner's manual or, in worst case, they are associated with the car's VIN and you can contact the manufacturer. Just so it doesn't surprise you when nothing works (or the owners).
 
#5
I'm sure it's the right thing to do, but I don't. Reason being is that the ground on my stud gun is a ring that runs around the center electrode. The current is confined to a very small area of sheet metal. This is not meant to be advice, just my experience. The only time I fried any electronics was by using a MIG welder to weld the body on a Range Rover and stupidly putting the ground clamp on the frame. That was expensive. Point being that IMHO the real danger lies in having the ground far away from the work.
 
#6
Thanks for the replies, guys. I am going to take both cables off as I just can't take any chances. I discussed it with the customer and he said he knows a local whiz bang mechanic that can retrieve/input any code requirements if that is needed. Crash, my stud gun is like yours with the center electrode inside a grounded ring. I never considered that the current remains inside the ring but it does seem logical. I think I learned something today!!
You guys are the best. Thanks
 

Chris_Hamilton

Trying to be the best me, I can be
#7
+1 for what Crash said. Exactly what I was going to say.:) Done it for years, never had an issue. Lots and lots of cars, like Crash said the ground contains the electrode so theoretically the current stays there.
 

EddieF

Top Banana
#8
Crash- you leave batt alone for mig & arc too?
This is also something i've wondered long time.
Edit- Alone meaning leave pos & neg connected to batt.
 

Chris_Hamilton

Trying to be the best me, I can be
#9
Eddie not a good idea but you can. Like Crash said you want the ground clamp very close to the work(area being welded). That being said it's a good idea to always disco the cables and use something like this: Z_pO6zmcpEx-.JPG

Newer vehicles have multiple computers in various locations, any welding can fry something close to where you are welding even with one of these attached. Always a good idea to pull any electronics near where you are welding, e.g. quarter panels, rear body panels, rockers.
https://www.zoro.com/otc-antizap-au...xriYq63aVw0lDPhWb0pze0Wpen3ykJKRoChf4QAvD_BwE
 
#10
Thanks Chris. So now i have to wonder what's in it heh. Capacitors?
I stay away from new cars. My newest is a 93 :) Exhaust been welded on, left batt connected.
Trying to think what happens with voltage spikes if both batt cables were connected together.
Hmmm..
 

Chris_Hamilton

Trying to be the best me, I can be
#11
That vintage GM you should be ok with just battery disco. Although GM's of that vintage are quirky. Years ago I cut a wire once in a door harness and then soldered it back, trying to save time. Little did I know that it was something related to the anti theft system. The anti theft fried the computer and I ended up having to pay for replacing it. Never did that again.
 
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