Cummins Fan Clutch Not Working

Since you can make the fan work by manualy grounding it is not a mechanical failure of the fan clutch but a command failure.

Cummins fan clutch not working.

Keep an eye on the temperature gauge indicator on the instrument panel. This can cause bearing damage radiator damage if the blades flex too far or even shatter a plastic fan. This video demonstrates the typical characteristics of a bad fan clutch. If the ac can turn it on through the ecm pcm so can the engine temp.

There are a few simple ways to test the fan clutch as make sure that it is functioning properly. Replacing your fan clutch can improve your a c system and keep the engine cooler. The fan clutch is an electronically controlled part that attaches to the fan on the front of your motor and causes air to be forced into the cummins a c system. Excess fan noise at high speed is caused by the same problem a seized fan clutch.

On a functional fan clutch the fan blades will all be lined up neatly inside the housing which should sit upright with an equal amount of space between the radiator and engine. If your driving around in hot weather and your a c is blowing cold then the fan clutch is working at that time. Keep an eye out for any visible components that are bent crooked or missing. The pcm uses readings from several different sensors to tell the fan when to come on and for how long and at what speed.

If the fan rotates when you turn on the engine or the fan does not work after four or five minutes when the engine reaches operating temperature replace the clutch. Fan spins after engine shut down might indicate a weak clutch.