Quote Originally Posted by Trip59 View Post
Small project tomorrow morning, radiator support cracked on my friend's Peterbilt, down at the bottom where the hood strut bolts to. It's not that thick, not worried about the weld itself even though I'm stuck using the small Hobart I have, my question is, do I have to worry about onboard electronics at all?
Since no high frequency, there is a lot less danger. Most devices have labels that caution you to disconnect the battery when welding. Some things like MSD modules require they be removed before welding. It's never a bad idea to disconnect power before welding, but I can't say that I always do. The big thing is to make sure you have your ground clamp as close as possible to the weld, and to make sure it's a real good connection. Otherwise the ground path might go through things that won't like it.
I saw a guy welding a body panel on an MG midget, where he had the ground clamp on the frame. Everything went fine until he tried to move the car later. It seems that the welders ground path went via the choke cable and welded it solid.