Engine Cooling Fan Does Not Operate With A/C On

1. Turn ignition switch to RUN position and turn A/C switch to ON position. If engine cooling fan operates, system is operating properly. If engine cooling fan does not operate proceed to step 2. Turn ignition switch and A/C switch OFF.
2. Check fan relay fuse link. If fuse link is blown, replace link and check for shorts to ground. If fuse link is satisfactory, proceed to step 3.
3. Disconnect engine cooling fan electrical connector and turn ignition switch to RUN position and A/C switch to ON position. Using a suitable voltmeter, check for battery voltage at motor feed terminal (black-red striped wire). If battery voltage is obtained, proceed to step 4. If battery voltage is not indicated, connect engine fan electrical connector and turn ignition and A/C switch OFF.
4. Connect a suitable jumper wire from cooling fan ground terminal (brown-black) to a clean chassis ground. Turn ignition switch to RUN position and A/C switch to ON position. If engine cooling fan does not operate, replace fan motor. If engine cooling fan operates, repair open circuit in fan motor ground circuit. Remove jumper wire, turn ignition and A/C switches to OFF position.
5. Using a suitable voltmeter, check for battery voltage at engine cooling fan relay motor terminal (black-red stripe wire). Turn ignition switch to RUN position. If battery voltage is obtained, repair open circuit from relay motor. If battery voltage is not indicated, proceed to step 6 and turn ignition and A/C switches to OFF position.
6. Using a voltmeter, check for battery voltage at engine cooling fan relay (battery red terminal). If battery voltage is not indicated, repair open in engine relay battery feed wire. If battery voltage is measured, proceed to step 7.
7. Using a voltmeter, check for battery voltage at engine cooling fan relay coil terminal (black-white stripe wire). Turn ignition switch to RUN position and A/C switch to ON position. If battery voltage is not indicated, proceed to step 9. If battery voltage is obtained, proceed to step 8.
8. Connect a jumper wire from engine fan relay ground terminal (brown-black stripe wire) to a clean chassis ground. Turn ignition switch to RUN position and A/C switch to ON position. If engine cooling fan does not operate, replace engine fan relay. If engine fan operates, repair open circuit in engine fan relay ground circuit.
9. Using a voltmeter, check for battery voltage at A/C switch engine fan relay terminal (buss bar with black-white stripe wire). Turn ignition switch to RUN position and A/C switch to ON position. If battery voltage is not indicated, check circuit. If battery voltage is obtained, repair open in wire from A/C switch to engine fan relay.