How Do You Diagnose Radiator Fans Not Coming On?
Radiator fans that don’t come on pose a serious problem because this could cause overheating and inevitable engine damage if driven for long periods of time. Therefore, it is important not to drive the vehicle until the fans are operable again. Diagnosis is relatively straightforward and should only take a couple hours. With the engine on and at operating temperature, disconnect the fan connector and measure the voltage with a multimeter. To do this, connect the red plug to one prong in the connector and the black plug to the other prong. You should see 12V. If you do, then there is something wrong with your fan and needs to be replaced. If you aren’t getting 12 V, move on to the next step. Measure the electrical resistance between the fan connector and the fan relay. You will need the vehicle’s electrical schematic to know which prong to probe at the relay and connector. You should see 0 ohms. If there is continuity, move on to the next step. If there is no continuity, there is a brea
