Hi Fellas

The truck's a '03 1500 4X4 4.7L V8.

I'm extremely curious as to why the radiator fan goes on immediately when I turn on the ignition - even in sub-zero temps! I can't say that I'm a mechanical wizard, but is this something that the '03s just do??? Any ideas?

Thanks in advance for any thoughts, Gents. Cheers

 

radiator or condenser fan, I have the understanding the 4.7 is a belt driven fan for the engine.

 

Condenser fan or radiator fan? Do you have the defroster on? That would make the condenser fan come on. Does the truck have automatic climate control? It would decide to run the defroster. If it's the radiator fan, your fan clutch is bad.

 

Hi Guys

Most definately the radiator fan. Judging by your comments, I am inclined to suspect a bad fan clutch. However, when I Googled the query I came across (in Yahoo Answers) a guy with a 2001 Takoma Prerunner with the same problem. One response suggested "unless its a clutch fan. Then Yes, its suppose to be on as long as the engine is running."

Is that true???

Thanks for taking the time to help!

 

Wait a second. Is the fan Mechanical or electric? Mechanical clutch fans will be engaged until the bay reaches operating temps. This is because the silicone inside the clutch is too thick to allow for the clutch to disengage.

If it's electric, it may be that your windshield defroster is on.

 

That's a bit backwards. The clutch will engage once the thermostat in the fan hub determines the air coming through the radiator is too hot. That's when the clutch grips the water pump shaft and spins the fan. There is no need for the fan until the fan clutch thermostat reaches a certain temperature, especially since little or no coolant is passing through the radiator.

 

i have a new to me 06 ram with the 5.7 i noticed my rad fan comes on when cold too, but it kicks out when going about 20 mph or a little bit into 2nd gear. so i know its not locked into position....or is my condition different?

 

The radiator fan.

Mechanical or Electric?

 

This is normal operation, the clutch cannot disengage the fan until the truck has warmed up enough to allow it to do so.

My truck does this, as does nearly every dodge I've ever seen.

If you are looking at the condenser fan, well that will turn on at any time if you have the defroster on, or if you have "auto climate control"...

 

If you take a moment while visiting your neighborhood Dodge dealer, try to turn the fan with the motor off. It will definitely spin, so the clutch is most assuredly disengaged when the motor is cold. When the motor is cold, why would there be any need for cooling?