Jeep Repair: radiator fan not working, radiator fan, jumper wire

Question
I have 2000 grand jeep cherkee....I replaced radiator and fan plus relay under headlight truck began run hot so I replaced thermostat still runs hot. When sitting still over time runs hot but going down road doesn't run hot but A/C doesn't get cold unless going fast.why fan won't work..

Answer

Fan Relay You'll need a 12v test light to check the relay wiring. With the ignition on, connect the test light to cavity 4 and ground, it should light up. If not, check the fuse for the fan and look for any broken wires. Connect the test light to cavity 1 and the battery + terminal, it should light, if not you have a broken ground. Finally, if there is power at cavity 4, connect a jumper wire between battery + and cavity 3, the fan should run. If not you either have a faulty fan motor or broken wiring. If all the above test pass, you will need to take the vehicle to a repair shop to have the fan control circuit from the PCM tested as this is something that requires special tools and knowledge.


RADIATOR FAN RELAY - BLACK 4 WAY CAV CIRCUIT FUNCTION
1 Z1 20BK GROUND
2 C24 20DB/PK RADIATOR FAN RELAY CONTROL
3 C23 12DG RADIATOR FAN RELAY OUTPUT
4 A16 12GY FUSED B(+)