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Dodge Radiator Fan Wiring Diagram — How the fan is wired

Get your radiator fan working again with this Dodge Radiator Fan Wiring Diagram

Most Dodge vehicles have a solid state radiator fan controller that varies the fan speeds by pulsing the ground to the radiator fan motor. However, older Chrysler and Dodge vehicles use a more traditional radiator fan relay. This is the Dodge Radiator Fan Wiring Diagram for the traditional version.

How the Dodge Radiator Fan Works

The powertrain control module (PCM) sends a reference voltage to the engine coolant temperature sensor and monitors the return voltage. When it determines the engine requires cooling, it grounds the control coil in the radiator fan relay. That energizes the coil and causes the relay contacts to close. Power then flows from the fuse in the integrated power module through the relay contacts and to the radiator fan motors.

Dodge radiator fan wiring diagram

Dodge radiator fan wiring diagram

How to troubleshoot the dodge radiator fan

Always start by checking the fuse for the radiator fans. It’s located in the integrated power module in the engine compartment. If the fuse is good, move on to the radiator fan relay.

Using the Dodge radiator fan wiring diagram above, you’ll see that the relay ground is at G102 and the control coil receives power from the PCM. The PCM won’t provide power until the engine coolant temperature sensor reading reaches the set amount. You can run the engine while monitoring the ECT using a scan tool with live data. If the ECT shows above 220°F (check the shop manual for the exact temp), you should see power on the dark blue/violet wire. If not, check for an ECT problem.

If you do see power, but there’s no power at the radiator fans, suspect a bad radiator fan relay. Swap it with another relay of the same size.

©, 2019 Rick Muscoplat

Posted on by Rick Muscoplat



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