Bypass Starter for Manual Crank Test

What happens here

With the starter not engaging from the ignition, the crew decides to manually bypass the starter to see if the engine will crank. The starter is located deep within the bell housing, similar to a small block Ford setup. A special jumper wire is used to directly apply power to the starter solenoid, bypassing the ignition switch. When activated, the starter successfully turns over the engine, confirming that the starter motor itself is functional but there's an issue with the signal from the ignition or a relay. The mechanic explains this is a common feature on 6.0L Ford Super Duty diesel engines to bypass the complex starting system for diagnostic purposes.

Goal: Verify starter motor functionality by bypassing the ignition system.