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Diagnostic Aids

WARNING: This page is about a different car, the 1995 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when instructed during QUICK TEST or if directed by other test procedures. This test is used to diagnose the following:

Fig 1: WAC Test Circuits & Connector Terminal ID (Ranger)
G95A27227

1)  DTC P1460: Verify ACCS PID Is Off

Turn ignition off. Ensure A/C and defroster are off. Connect scan tester to Data Link Connector (DLC). Start engine and allow to idle. Using scan tester, access ACCS PID. If ACCS PID is off, go to next step. If ACCS PID is on, go to step 20).

2)  Check VPWR Circuit

Turn ignition off. Disconnect WAC relay wiring harness connector. Turn ignition on. Measure voltage between VPWR terminal at connector and chassis ground. If voltage is 10.5 volts or more, go to next step. If voltage is less than 10.5 volts, repair open in VPWR circuit and repeat QUICK TEST.

3)  Check WAC Relay

Leave ignition off and WAC relay disconnected. Check resistance between terminals No. 85 and 86 at WAC relay. See Fig 2. Resistance should be 40-85 ohms. Check resistance between terminal No. 85 and terminal No. 30, 87 and 87A at WAC relay. Resistance should be more than 10,000 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace WAC relay and repeat QUICK TEST.

Fig 2: WAC Relay Connector Terminal ID (Ranger)
G95A12617

4)  Check WAC Circuit

Turn ignition off. Leave WAC relay disconnected. Disconnect PCM wiring harness connector. Inspect connector for damage or corrosion, and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Turn ignition on. Measure voltage between test pin No. 69 (WAC) at breakout box and chassis ground. If voltage is one volt or more, repair circuit short to power and repeat QUICK TEST. If voltage is less than one volt, go to next step.

5)  Turn ignition off. Disconnect scan tester from DLC. Measure resistance between test pin No. 69 (WAC) and test pins No. 51, 91 and 103 (PWR GND) at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is less than 10,000 ohms, repair circuit short to ground and repeat QUICK TEST.

6)  Leave ignition off and relay disconnected. Measure resistance between breakout box test pin No. 69 and WAC terminal at relay connector. If resistance is 5 ohms or more, repair open circuit and repeat QUICK TEST. If resistance is less than 5 ohms, replace PCM and repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 6) to step 20). No test procedures have been omitted.

20)  Turn ignition off. Connect scan tester to Data Link Connector (DLC). Disconnect A/C Pressure Switch (ACPSW). Using scan tester, access ACCS PID. If ACCS PID is on, go to next step. If ACCS PID is off, check A/C demand switch, and repair or replace as necessary.

21)  Leave ignition off. Disconnect WAC relay wiring harness connector. Measure voltage between POWER-TO-CLUTCH terminal of connector and chassis ground. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair circuit short to power and repeat QUICK TEST.

22)  Turn ignition off. Leave ACPSW and WAC relay disconnected. Disconnect PCM wiring harness connector. Inspect connector for damage or corrosion, and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Turn ignition on. Measure voltage between test pin No. 41 (ACCS) and test pins No. 51 and 103 (PWR GND) at breakout box. If voltage is one volt or more, repair circuit short to power and repeat QUICK TEST. If voltage is less than one volt, go to next step.

23)  Turn ignition off. Leave ACPSW disconnected. Reconnect WAC relay. Turn ignition on. Measure voltage between test pin No. 41 (ACCS) and test pins No. 51 and 103 (PWR GND) at breakout box. If voltage is one volt or less, replace PCM and repeat QUICK TEST. If voltage is more than one volt, replace WAC relay and repeat QUICK TEST.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 23) to step 30). No test procedures have been omitted.

30)  Continuous Memory DTC P1460

Turn ignition off. Leave WAC relay disconnected. Disconnect PCM wiring harness connector. Inspect connector for damage or corrosion, and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Turn ignition on. Connect DVOM between test pin No. 69 (WAC) and 71 (VPWR). Voltage should be 10 volts or more. Observe DVOM for indication of fault while wiggling and bending WAC circuit between WAC relay and PCM. Fault will be indicated by fluctuation in voltage reading. Wiggle and bend VPWR circuit between EEC-V power relay and WAC relay. Lightly tap on WAC relay. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, go to next step.

31)  Turn ignition off. Connect scan tester to Data Link Connector (DLC). Turn ignition on. Using scan tester, access WACA PID. Scan tester should show WACA PID on. Observe WACA PID for indication of fault while wiggling and bending WAC circuit between WAC relay and PCM. Fault will be indicated by WACA PID turning off. Check connectors for clean tight connection. If any faults are found, isolate and repair as necessary. If no faults are found, fault cannot be duplicated at this time. Go to CIRCUIT TEST Z.

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