(1) Disconnect the connector, and measure at the wiring harness side.
(2) Check the continuity between the PHEV A/C amp. connector (WP terminal) and body ground.
OK : No continuity
(3) Check the continuity between the PHEV A/C amp. connector (WP terminal) and heater water pump.
OK : Continuity exists (2 Ω or less)
Is the inspection result normal?
Repair harness or connector.