Automotive Air Conditioning Information Forum

I’ve had three coworkers over the years ask me to check their ac on their diesel trucks. Always the same story, works ok, but not as cool as other vehicles they’ve drove. Didn’t find any problems on any of the three. Is it possible that the cooler running diesel motors don’t require the radiator cooling fan to run as much as a fan does on a gas burner? These trucks ranged in age from 1996 to 2014.

I can tell you the blend door on the 2005 gen will break causing the heater core to mix with the AC and make you think its not working well. The other problem is the outside/cabin vent door will break or the seal will fall off and cause it to feel warmer when moving. come to a stop and it works fine. Personally experienced and fixed both of these. we still have the 2005. Great truck and they make plenty of heat. They all have a mechanical fan so there is no flow issues.

Diesels run much slower rpms than gasoline-- so the compressor hardly ever goes above 2000 rpm- and they idle much slower as well