350-8457 3508457 Chassis Main Harness for 390D Excavator

Installing a chassis harness is a meticulous process. Always refer to the official Caterpillar Schematics (SIS Web) and the machine's Disassembly and Assembly Guide. Safety is paramount.

Preparation (Pre-Installation)
Power Down: Disconnect the negative (-) battery cable(s) from both batteries. Isolate the cables to prevent any accidental contact.
Obtain Correct Parts: Ensure the new chassis harness (Part Number specific to the 374F serial number) and any necessary connector seals or repair kits are on hand.
Prepare the Work Area: The machine should be on a clean, level surface. Thoroughly clean the main frame to remove dirt and debris that could enter connectors or abrade the new harness.
Label Connectors (if replacing old harness): Before removing the old harness, take photos and use tags to identify all connection points. This serves as a visual guide during installation.