Hey,

the other night i was sitting in my driveway waiting for the AC to warm up and both the electric cooling fans kicked on and i've never realized how much of a power draw they create. The tach actually drops when they kick on. Should it be that bad? and aren't there aftermarket cooling fans that you can buy, like a single fan thats bigger than the twin fans? just wondering. thanks guys.

howard

 

The power drop could have been due to both the fan and/or the a/c compressor cycling on. It's nothing to worry about. Our car's engine is regulated by an ECU that knows whether your a/c is on, and how much of an electrical drain is present on the system.

I would strongly advise against replace both stock fans with one big one. Note that the purpose of one of the fans is to cool the radiator, the purpose of the other fan is to cool the a/c condenser. Using one big fan will cause you to loose the ability to independently control the two. You will use more energy this way.

Just my two cents.

 

yeah well i dont even have the a/c on and i've popped the hood to check and anytime any of them come on both of them come on at the same time, i've never seen one come on without the other one being on. do they ever come on independantly? i didn't know that they had different uses, thanks bebber i guess you learn something new everyday eh? lol

howard

 

I agree with bebber. From my past experiences with cars in general, the two fan set-up is pretty standard with one being dedicated for the radiator and the other cycling on and off for the a/c compressor. If your tach was dropping, then that was probably due to the clutch engaging on your a/c compressor, which is belt driven and robs your enging of power.

Also note that whenever you put your front defroster on, the a/c comes on as well. You can turn the a/c off by pushing the a/c button on climate control console and keep the compressor from coming on during defrost.

I also found that if you leave your climate control system to "full auto", that your a/c cycles on and off as deemed necessary by the car's computer system. Once again, you can shut off the a/c portion and just have the car in "auto" mode, which still allows for circulation and at the same time improves your gas mileage because you won't be using the a/c.

If you had your climate control system in "full auto" mode or were using the front defroster, then this may account for why both fans were on when you didn't have the a/c on when you checked under the hood.

 

The two fans do operate independently, however I believe that both come on when you engage the A/C. Also, the ECU richens the air/fuel ratio just a bit when the A/C is engaged (to smooth the feeling of its engagement). This, plus the additional electrical load (detected by none other than the.. Electrical Load Detector) results in a slight dip in engine speed when the A/C is engaged.