Diagnostic Aids

WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when instructed during SYMPTOM DIAGNOSIS or another SYSTEM TEST. This test is intended to diagnose the following:

Harness circuits; A/C SIG, GND, PCM REF and PWR.
A/C relay.
High pressure switch.
PCM.

Fig 1: Identifying A/C Relay Circuits & Terminals

Courtesy of FORD MOTOR CO.

Fig 2: Identifying High Pressure Switch Circuits & Harness Connector Terminals

Courtesy of FORD MOTOR CO.