It's finally warm enough here in PA that I had the A/C on today. But, when it's on everytime I accelerate the underhood fan gets louder. I know this is normal but I didn't know it would happen every time when the A/C is on, on my last truck it rarely ever happened. My brother in law has an '05 3500 CTD dually, he lives in S. Florida and have never heard his truck do it. Anyone know anything about this?

 

MIne is an 06 built 05/06. When it is warm enoughthat I have the A/C on I hear the fan from idle up to about 1500 RPM. This is normal, and if your brother in law took his truck in and complained abou the A/C performance they would flash his truck and it would do it too. Even with the fan that way the A/C performance is not all that great. Besides I think it sounds kinda cool.

 

Do the 03' use a viscous fan clutch like my 95', or do you have an electric fan?

If the fan is not electric, I would check the coolant level and quality. Your tstat could be sticking slightly.

My fan clutch NEVER engages to the point where I hear it rev with the motor. My cooling system never get's that hot.

Anyway, good luck with your ride.

 

The newer trucks have a electronically controlled viscous clutch. The computer can command the clutch at any percentage it wishes toup to 100%. They use that to pre-empt any cooling issues and to help the poor A/C do it's job.

 

and it always makes me wonder why the fan is right next to the engine yet the condensor is at the front. . .very little airflow at slow speeds.

BTW, I do hear mine on occasion when it's hot out.

 

He never took it in, but he says that his truck does it every now and then. However I lived down there for a while and would drive his truck several times a day everyday and I never heard it. I just don't understand why mine does it all the time (like u said up to @ 1500 rpm) when the A/C is on. Should I check the coolant level. Drew, u even said yours only does it once in a while. As soon as I shut the A/C off it stopped.[:@]

 

it kicked on once over the weekend pulling a trailer up some good grades with the A/C on. . .temps outside were about 78F and I was showing off next to an 08 F350

other than that it might kick on seldom when I'm showong off around town with the windows down no A/C