LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 1996 >> Aerostar Van Window >> Repair and Diagnosis (Single Page) >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC System - Basic Trouble Shooting - Manual >> Diagnosis - Villager >> Insufficient Or No A/C Cooling

Insufficient Or No A/C Cooling

  1. Check A/C Compressor Clutch Operation

    Start engine and set A/C to maximum. If A/C compressor clutch does not engage, go to next step. If the A/C compressor clutch engages, go to step 20).

  2. Check Refrigerant System Pressures

    Check A/C system performance. See TESTING in MANUAL A/C-HEATER SYSTEMS -VILLAGER article. If pressures are not okay, service system as necessary. If pressures are okay, go to next step.

  3. Check Fuses

    Check RELAYS fuse (10-amp) and A/C CONT fuse (7.5-amp) in interior fuse relay block. If fuses are okay, go to step 10). If any fuse is blown, go to next step.

  4. Check System

    Ensure ignition is off. Replace any blown fuse. Turn ignition on. Recheck fuses. If fuses are okay, go to step 11). IfA/C CONT fuse is blown, go to step 8). If RELAYS fuse is blown, go to next step.

  5. Check For Short To Ground In RELAYS Fuse Circuit

    Ensure ignition is off. Remove RELAYS fuse from interior fuse block. Remove AIR CON relay from engine compartment right relay block. Using ohmmeter, measure resistance of Blue wire between interior fuse relay block and ground. Resistance should be greater than 10,000 ohms. Measure resistance of Blue wire between RELAYS fuse and AIR CON relay. Resistance should be less than 5 ohms. If resistances are as specified, go to step 10). If resistances are not as specified, go to next step.

  6. Check Blue Wire To AIR CON Relay

    Ensure ignition is off. Disconnect engine compartment fuse/relay junction connector No. 1. Remove AIR CON relay from engine compartment right fuse/relay block. Using ohmmeter, measure resistance of Blue wire between interior fuse/relay block and ground. Resistance should be greater than 10,000 ohms. Measure resistance of Blue wire between RELAYS fuse and AIR CON relay. Resistance should be less than 5 ohms. If resistances are not as specified, repair Blue wire as necessary and retest system. If resistances are as specified, go to next step.

  7. Check Junction Connector No. 1 For Continuity

    Ensure ignition is off. Disconnect engine compartment fuse/relay junction connector No. 1. Measure resistance of Blue wire between terminals of junction connector No. 1. If resistance is greater than 5 ohms, replace junction connector No. 1. If resistance is less than 5 ohms. repair Blue wire between RELAYS fuse (10-amp) and junction connector No. 1. Retest system.

  8. Check For Short To Ground In A/C CONT Fuse Circuit

    Ensure ignition is off. Remove AIR CON relay from engine compartment right relay block. Disconnect front A/C control panel 12-pin connector. Replace A/C CONT fuse (7.5-amp). Turn ignition on. Turn A/C on. If fuse fails again, go to next step. If fuse does not fail repair Gray/Blue wire and retest system.

  9. Check For Short To Ground Between AIR CON Relay & A/C Compressor Clutch Circuit

    Ensure ignition is off. Remove AIR CON relay from engine compartment left relay block. Disconnect A/C compressor clutch connector. Measure resistance of Gray/Red wire between AIR CON relay connector and A/C compressor clutch connector. Resistance should be less than 5 ohms. Measure resistance of Gray/Red wire between AIR CON relay connector and ground. Resistance should be greater than 10,000 ohms. If resistances are as specified, go to step 10). If resistances are not as specified, repair Gray/Red wire as necessary. Retest system.

  10. Check A/C Compressor Clutch Signal

    Warm engine to normal operating temperature. Turn ignition off. Disconnect A/C compressor clutch connector. Ensure A/C is off. Measure voltage of Gray/Red wire at A/C compressor clutch. Voltage should be less than 1 volt. Turn A/C system on. Measure voltage of Gray/Red wire at A/C compressor clutch connector. Voltage should be greater than 10 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 17).

  11. Check Power Supply To AIR CON Relay

    Ensure ignition is off. Remove AIR CON relay from engine compartment left relay block. Turn ignition on. Measure voltage at Gray/Blue wire and Blue wire terminals of AIR CON relay connector. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair appropriate wire.

  12. Check AIR CON Relay

    Ensure ignition is off. Remove AIR CON relay. Connect a jumper wire between Blue wire terminal of AIR CON relay and positive battery terminal. Connect a second jumper wire between Gray/Red wire terminal (circuit to PCM) of relay and negative battery terminal. Using ohmmeter, check continuity between Gray/Blue wire and Gray/Red wire terminals of relay. Ohmmeter should read less than 5 ohms, indicating continuity. Disconnect jumper wire between Gray/Red wire terminal and negative battery terminal. Check continuity between Gray/Blue wire and Gray/Red wire terminals of relay. Ohmmeter should read greater than 10,000 ohms, indicating no continuity. If continuity is as specified, go to next step. If continuity is not as specified, replace AIR CON relay.

  13. Check AIR CON Relay Circuit To PCM

    Ensure ignition is off. Disconnect AIR CON relay connector and Powertrain Control Module (PCM) connector. Measure resistance of Gray/Red wire (Light Green wire after splice) between relay connector and PCM connector. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, repair open wire.

  14. Check Power Supply To A/C Control Panel

    Ensure ignition is off. Disconnect A/C control panel 12-pin connector. Turn ignition on. Measure voltage at Gray wire terminal of A/C control panel connector. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair Gray wire between interior fuse block and A/C control panel.

  15. Check A/C Pressure Cut-Off Switch

    Ensure ignition is off. Disconnect A/C pressure cut-off switch connector. Measure resistance between Brown wire and White/Red wire terminals of A/C pressure cut-off switch. If resistance is less than 5 ohms, go to next step. If resistance is greater than 5 ohms, replace A/C pressure cut-off switch.

  16. Check Wire Between A/C Cycling Switch & A/C Pressure Cut-Off Switch

    Ensure ignition is off. Disconnect A/C pressure cut-off switch connector. Disconnect A/C cycling switch connector, located on accumulator-drier. Measure resistance of Brown wire between A/C pressure cut-off switch and A/C cycling switch connectors. Resistance should be less than 5 ohms. Measure resistance of Brown wire between A/C pressure cut-off switch connector and ground. Resistance should be greater than 10,000 ohms. If resistances are as specified, go to next step. If resistances are not as specified, repair Brown wire and retest system.

  17. Check A/C Cycling Switch

    Reconnect A/C pressure cut-off switch. Run engine until normal operating temperature is reached. Turn ignition off. Disconnect A/C cycling switch connector. Connect jumper wire between Brown/White wire and Brown wire terminals of connector. Start engine, and turn A/C on. If A/C compressor clutch engages, replace A/C cycling switch. If A/C compressor clutch does not engage, go to next step.

  18. Check Wire Between A/C Control Panel & A/C Cycling Switch

    Ensure ignition is off. Disconnect A/C cycling switch connector. Disconnect A/C control panel 12-pin connector. Measure resistance of Brown/White wire between A/C cycling switch connector and A/C control panel 12-pin connector. Resistance should be less than 5 ohms. Measure resistance between Brown/White wire terminal at A/C cycling switch connector and ground. Resistance should be greater than 10,000 ohms. Resistances are as specified, replace A/C control panel. If resistances are not as specified, repair Brown/White wire.

  19. Check A/C Compressor Clutch

    Ensure ignition is off. Disconnect A/C compressor clutch connector. Connect a jumper between Black wire terminal of A/C compressor clutch and negative battery terminal. Connect a second jumper wire between Gray/Red wire (White/Orange wire after splice) terminal of A/C compressor clutch and positive battery terminal. Ensure clutch hub is pulled in when battery voltage is applied to A/C compressor clutch. Remove jumper wire between a/C compressor clutch and positive battery terminal. Ensure clutch hub is released when jumper wire is removed. If clutch hub functions as indicated, repair Black wire between A/C compressor clutch and ground. If clutch hub does not function as indicated, replace A/C compressor clutch.
scientia non olet · About LEMON Manuals