Circuit Test D4 - Wot A/C Cut-Off (Acc)

Fig 1: ACC Circuits

NOTE: Enter this test only when directed here from another CIRCUIT TEST procedure. This test is intended to diagnose only the following: A/C pressure switch, ECA, and harness circuits (A/C relay and pressure switch)

1. Checking System Integrity  - Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.
2. Checking Voltage From A/C Relay  - Install breakout box and set VOM on 20-volt scale. Leave ECA disconnected. With KOEO, measure voltage between test pins No. 30 and 20 (ground). If voltage is less than 10 volts, go to step 3). If not, go to step 4).
3. Measure Voltage At A/C Relay No. 1  - Set VOM on 20-volt scale. Leave ECA disconnected. Ensure A/C relay No. 1 is connected. DO NOT  pierce wire during test. With KOEO, measure voltage between "GN/R" wire at A/C relay No. 1 and ground. If voltage is less than 10 volts, repair or replace A/C switch or relay. If not, repair "GN/R" wire between ECA and A/C relay No. 1.
4. Checking A/C Circuit For Short To VPWR  - Install breakout box and set VOM on 20-volt scale. Leave ECA disconnected. Disconnect A/C relay No. 1. With KOEO, measure voltage between test pins No. 30 and 20 (ground). If voltage is greater than zero volts, repair short to VPWR. If voltage is zero volts, go to next step.
5. Checking Voltage From A/C Pressure Switch (ACPS)  - Install breakout box and set VOM on 20-volt scale. Leave ECA disconnected. With KOEO, measure voltage between test pins No. 14 and 20 (ground). If voltage is less than 10 volts, go to step 6). If not, go to next step.
6. Checking Voltage At ACPS  - Disconnect ECA and set VOM on 20-volt scale. Leave ACPS connected. DO NOT  pierce wires during test. With KOEO, measure voltage between "BL/BK" wire at ACPS and ground. If voltage is less than 10 volts, go to step 8). If not, repair "BL/BK" wire between ECA and ACPS.
7. Checking ACPS Circuit For Short To VPWR  - Install breakout box and set VOM on 20-volt scale. Leave ECA disconnected. Disconnect A/C relay No. 1. With KOEO, measure voltage between test pins No. 14 and 20 (ground). If voltage is greater than zero volts, repair short to VPWR. If voltage is zero volts, replace ECA.
8. Checking Voltage To ACPS  - Disconnect ECA and set VOM on 20-volt scale. Leave ECA disconnected. With KOEO, measure voltage between "BL/GN" wire at ACPS and ground. If voltage is less than 10 volts, repair or replace A/C switch or relay. If not, replace ACPS.