ISC Fan Clutch Replacement $4000+ ?

elhajj33 wrote:

Ivylog wrote:
Your fan should not come on until the water temperature gets above 185°. You have a water temperature sensor probably close to the thermostat that is normally open until it senses 185°. When it closes it provides the ground to close a relay that provides the 12 votes to magnetize the fan clutch.

got to the bottom of it! I called horton and confirmed that the clutch is engaged at zero volts- that was a good sign as the clutch was not getting voltage. I also freightliner; they confirmed the fan come on as soon as the engine starts and stays on for about 30seconds until the ECM sends a signal to the clutch.

Finally, Freighliner suggested the fan clutch fuse might have blown. This seemed very likely since the serpentine belt did snap the wires.

I checked the fuse and, wouldn't you know it, it had blown! I just need to run out now and get a 5A mini fuse (it's one of the ones I don't have onboard).

i was so relieved that it wasn't the clutch! I'll report back when it's all up and running.

Thanks everyone for helping me out!