Automotive Welding

[Brill757]

Hello to my fellow welders
My question involves welding on automobiles, anything from 18 wheelers to Datsun B-210 (now that’s retro for ya . I want to spot weld some replacement panels on my 85 GMC CK-1500, are there any special grounding requirements that I need to do before hand so that I don't fry my electrical system? I've read somewhere on the net, all you have to do is disconnect your negative battery terminal. Just to be on the safe side, could someone please provide me some info it would greatly be appreciated. Thanks in advance and "KEEP BURNING"

[SeanMurphy265]

Be sure to unplug the battery! Also you want your ground close, you never want to ground somewhere the current runs through a bearing. This could cause an arc to jump in the bearing and ruin a bearing. I learned this by taking a good butt chewing, followed by a nice explanation of why I should not do that again, and also how much it cost the owner 20 years ago to replace a bearing in a truck.

[Brill757]

Thank you very much for the info, wow I did not expect such a quick reply. Your help is greatly appreciated.

[Wrenchtamer]

Thank you very much for the info, wow I did not expect such a quick reply. Your help is greatly appreciated.

Hi. I am an ASE Master Tech/L1 Diagnostic Specialist. I have been working with cars for a long time and I have some technical knowledge others may not. Yes, it is a good idea to disconnect the negative cable. I disconnect BOTH terminals. I also disconnect certain sensors which provide a direct ground to the PCM. Coolant temp sensor, ETC. Most of the time you could not take these precautions and everything would be fine. But the one time you dont... It has happened to me. 01 Chrysler PT cruiser. I killed the low side driver in the pcm that supplied the ground for one of the coil circuits. Expensive mistake, but not my worst....