Rising temperature when running air conditioner

In my '97 Outback and most modern cars there is an electric fan that cools the radiator and AC condenser, but it only operates when you are not moving. During normal travel the air flow through the radiator and condenser is sufficient to provide cooling without the fan, so it is shut down to save energy.

Either the thermostat that controls the fan is broken, or the fan is broken, or a fuse is blown or a wire is disconnected.

What is a "good" answer. Two of us have suggested the same thing: namely that the electrically operated fan used for the radiator and A/C condenser is not operating properly. Have to checked to see if the fan is coming on when you are standing still with the A/C operating?

-- Vic Roberts

Something that is free, and doesn't require any time or effort. ;)

Mark

compressor when

was concerned about

No, they don't cycle with the compressor. And, in some cars they can turn on AFTER the engine has been turned off (as the radiator temperature rises after you stop moving), so watch out for your hands if you play in the engine compartment.

-- Vic Roberts

Ed, my question was whether the fans are over-ridden by output from the vehicle speed sensor. In other words, there'd be no need to have the fans cycling with the compressor when the car's cruising down the highway. -Danny

speed sensor. In

when the car's cruising

The temperature sensor used to turn on some A/C condenser fans serves this same purpose. I don't know of any that have a speed sensor. A temperature sensor is both more direct and, I would assume, less expensive, since it does not require connection to any other systems.

-- Vic Roberts

vehicle speed sensor. In

when the car's cruising