2003 Malibu - A/C switch causing radiator fans to come on

I think the fan automatically come on when the AC is on.

That is correct. For the A/C to function, air must move across the condenser coil in order to expel the heat that has been removed from the cabin (absorbed by the evaporator coil). This operation sounds normal to me.

Interesting. I never noticed it before, but what you guys say makes sense, especially when the ambient air temperatures are in the "stinking hot" range.

Brad

@#@ Whenever the Ac. function is used the rad fans come on to keep the high pressure side of condenser below 250-300 psi this keeps pressures within the safe range. This is basically standard in most automotive ac. systems.

Rey

Yup it does......Dont matter what the outside temp is. My 89 Bonni fan comes on at half speed when the ac is on.... I hot wired it with a switch for full speed for when I get stuk in a traffic jam or when towing. Seems you had a problem last summer that has now fixed itself.

"" wrote: > I'm in eastern Ontario and have noticed this behavior during > the last > week or so during our heatwave (as well as the previous one > earlier this > month). > > When I start the car after it has sat outside for 8+ hours at > the bus > station in 30+ degrees Celcius weather, the radiator fans do > not come on > when the temperature guage is at 40 (cold) or even halfway. > > However, if I turn on the air conditioner when the temperature > guage is > at 40 (cold) or even halfway and the outside ait temperature > is really > warm, the the radiator fans come on. > > This did not happen last summer in similar heat conditions, so > I am > wondering if something got buggered up with the cooling system > when the > lower intake manifold gasket was repalced a few months ago. > > This only seems to happen when it is really hot outside. > > Any ideas what might be causing this? > > Thanks...Brad

By all rights the fans should come on with the A/C being that the condensor on the front of the radiator builds up alot of heat which in turns almost doubles the heat that the radiator has to cool plus the condensor has to stay cool as well for the A/C to work properly.