2001-peterbilt-379-fuse-panel-diagram Apr 2026

: Power for the diagnostic port (typically an orange wire with a red stripe).

For a 2001 Peterbilt 379 , the electrical system is spread across several key locations. While a single comprehensive diagram is rarely printed on one sticker, you can typically find the specific layouts you need in the following areas: Primary Fuse Panel Locations 2001-peterbilt-379-fuse-panel-diagram

: You can often find a "yellow box" or a silver housing on the passenger side firewall in the engine compartment. This area typically contains heavy-duty fuses or relays for the ECM and high-draw systems. : Power for the diagnostic port (typically an

: Some 379 models feature a smaller mini-fuse panel behind the steering wheel or near the instrument cluster. This area typically contains heavy-duty fuses or relays

: A 50A fuse near the batteries that controls all power to the cab.

: Often 5A (cab) or 30A (battery box) fuses dedicated to the engine control module. Troubleshooting & Resources