A/C Fan Does Not Operate, But Engine Fan Operates

1. Connect a suitable A/C gauge set and check for proper A/C refrigerant operation. If A/C refrigerant system is not operating properly, check refrigerant system. If A/C refrigerant system is operating properly, repair system and check A/C fan operation. Proceed to step 2.
2. Disconnect electrical connector from engine coolant temperature switch. Connect A/C gauge set. Set A/C controls for maximum cooling and open vehicle doors. If necessary, partially block airflow over condenser to increase high side pressure. If engine fan and A/C fan operate with high side refrigerant pressure reaches 254 psi, system is operating properly. If A/C fan does not operate with high side pressure at 254 psi, proceed to step 3. Connect coolant temperature switch electrical connector.
3. Connect a jumper wire from A/C pressure switch ground terminal (yellow-red stripe wire) to a clean chassis ground. Turn ignition switch to RUN position. If A/C fan operates, replace A/C pressure switch. If A/C fan does not operate, proceed to step 4. Turn ignition switch to OFF position and remove jumper wire.
4. Connect a jumper wire from A/C fan relay coil ground terminal (brown-black stripe wire) to a clean chassis ground. Turn ignition switch to RUN position. If A/C fan operates, repair open in wire from A/C fan relay to A/C pressure switch.