Radiator Ac Fan over speed problem

the radiator fan under the hood? if so, i think it's normal

 

Is this about the 2010 (third gen)? It's in the Prime forum. I'll see if a mod can move it.

The two fans up front behind the grille should always run when the A/C is on if I'm not mistaken.

There is both a low-speed and a high-speed mode. They should be running at low speed when the A/C is on, unless the engine is extra hot or the A/C pressure is extra high.

But my first question, simply, is: you say the fans are running in full speed ... but what observations have convinced you this is the high speed and not the low speed mode?

 

and if you're toyota, a/c fan is the cabin fan

 

I'm pretty sure if I were Toyota, that would be the "blower".



In fact, there's a little jargon-y bit that they are using correctly, where the kind of air-moving thingy that looks like an airplane propeller (like in front, behind the radiator) is a "fan", and the kind that looks like a squirrel cage and moves the air outward centrifugally is a "blower", as here (and also the one cooling the traction battery, which they also call a "blower").

Funny how, for all the weird things that happen in the Japanese-to-English translations, they do seem to consistently honor this rather geeky distinction in English.

 

i can't say it any better talha

 

1. I would question your premise that because the radiator fans are running full speed, that results in the reduction in fuel economy from 18 km/liter to 12.5 km/liter. I would say it is more likely that the air conditioner compressor power requirement is the major reason for the fuel economy reduction.

2. It could be that your air conditioning system is operating less efficiently due to slightly low refrigerant, which causes the compressor to run more than normal, thus worsening your fuel economy.

3. However, since you want to focus on the radiator fans as the issue, check the Fan #2 relay. That relay switches the two fans to either be in series, in which case the fan speed is reduced; or else they are in parallel for high speed. If that relay is stuck in the closed position, the fans will always be running at high speed whenever the engine ECM signals for the fans to operate.

 

There are two main categories of fans: axial-flow ("propeller") and centrifugal. They're free to call the latter variety blowers if they wish, but that doesn't keep them from being a subset of fans.

 

Among people who mark the distinction, 'blower' will be reserved for centrifugal, and 'fan' for axial. Not everyone marks the distinction, of course, but Toyota didn't invent it.

 

what was your solution to the problem?