C4: Check Core to Core Insulation

With connectors FC025, FC024, BT014 and BT015 disconnected measure the insulation resistance between FC025/013 and FC025/014.

- Is the resistance > 10 M ohms?
Yes
GO to C5 C5: Check Ground Continuity
No
Inspect harness/connectors FC025, FC024, FC001, BT004, BT014 and BT015 for corrosion, damage, bent or pushed back pins. Repair as required and test the system for normal operation.