Welding Current Damage
This is when, during electric arc welding on a vehicle or machine, the welding current finds its return path through electronic devices and destroys them. Welding current reaches hundreds of amperes; when the earth clamp is placed wrongly, part of that current flows through the wiring harness.
The welding machine current returns from the weld point to the earth clamp along the path of lowest resistance. If the clamp is attached far from the weld point, part of the return path may run through the harness, a sensor line or a board instead of the body. This current destroys semiconductors within milliseconds.
- Earth clamp: it is attached to clean metal as close as physically possible to the point being welded. This single measure removes most of the risk.
- Battery: disconnect both battery terminals before welding; disconnecting only the positive is not enough.
- Device connectors: unplug the connectors of drivers, remote control receivers and control boards.
- Recommissioning: after welding, reconnect and verify the functions one by one; damage sometimes shows up not immediately but in the following days.
On vehicles fitted with AXI remote controls, drivers and lift kits, these steps must be applied for every welding job done later. Weld-induced damage looks like a surprise failure because there is no installation error behind it.
Context in which this term is used: Installation, redundancy and field continuity