C3: Check For Short to Ground

With connectors FC025, FC024, BT014 and BT015 disconnected measure the insulation resistance between FC025/013 and FC024/026.

Repeat for FC025/014 and FC024/026

- Is the resistance > 10 M ohms?
Yes
GO to C4 C4: Check Core to Core Insulation
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.