GEAR 5M7740 - Caterpillar

Proper welding procedures are necessary to avoid damage to any control modules, sensors, and associated components. If removing components from an electronic engine that is being welded is not possible, the following procedure must be followed. This procedure provides the minimum amount of risk to the electronic components.
Do not ground the welder to electrical components such as the ECM or sensors. Improper grounding can cause damage to the drive train bearings, hydraulic components, electrical components, and other components.Clamp the ground cable from the welder to the component that will be welded. Place the clamp as close as possible to the weld. This will help reduce the possibility of damage.
Stop the engine. Remove the electrical power from all control modules that are on the engine.
Disconnect the negative battery cable from the battery. If a battery disconnect switch is installed, open the switch.
If your application is equipped with circuit breakers for the digital return, open these circuit breakers.
Illustration 1 g02724209
Service welding guide (typical diagram)
Connect the welding ground cable as close as possible to the area that will be welded. Components which may be damaged by welding include bearings, hydraulic components, and electrical/electronic components.
Protect the wiring harness from welding debris and from spatter.
Weld the materials by using standard welding methods.