Car Question-cooling fans?

[Diamondback]

I have a 94 Acura Legend. I don't know if this is a problem or not, but when I'm stopped or idling with the A/C on, I hear the cooling fan cycling on and off-kinda of like it's reving up and then back down. It will constantly do this. Now, I haven't had any problems with my A/C. The air blows out at a normal speed and the air is very cold. My question to anyone who knows a lot about cars, or better yet Acura Legends, is this normal and if not, what may be causing this? Is it something that I should worry about and how would I fix it?

 

[Ramathorn]

Don't know if this helps, but my friend has a Jetta and he had to replace his cooling fan. He had the same problems that you did. In his car, there were two fans, one for the ac, and I think the other was for the radiator.

If you can afford it, have a mechanic check it out. His fan was 170 bucks; he couldn't find a used one though.

Also, we had to remove the ac hose to take out the motor. If you have to do so, make sure you decompress the a/c.

 

[ryskey]

If it's the elecric fan for the radiator, it's supposed to cycle on and off. Since it's controlled by the thermostat, it will only turn on when the coolant gets above the specified temperature.

Are you sure the cycling isn't the compressor? If it is, you're probably low on freon.

 

[Diamondback]

How can I tell if it's the compressor and not the electric fan? I don't know that much about cars/engines, but when I turn the A/C off, the cycling goes away. I don't know if that helps in determining if it's the compressor or electric fan. Should I just check and see if the freon is low first and then add some?

 

[ryskey]

How to tell if it's the compressor:

Since your car is front wheel drive, your motor should be facing sideways. This means that your belt driven accessories will be facing the side of your car instead of the front. Your accessories (alternator, compressor, water pump- which is actually driven by your timing chain, but I digress) are driven by the long serpentine belt. Look for this belt rolling over a bunch of pulleys, which drive the accessories I just mentioned. If one of these pullies is cycling on and off as the belt goes over it, this pulley is connected to your A/C compressor, which means you're low on refrigerant. Take it to a mechanic to get it checked out.

Your radiator cooling fan should be located to the very front of the engine compartment on the radiator. If this is cycling on and off, don't worry. It's supposed to.

 

[accuratehorn]

Most Japenese cars have two electric fans. On Hondas, the two fans both come on for two reasons: when the radiator gets hot enough, about 180 degrees, they both come on to cool the engine, and they will cycle on and off according to the temp in the radiator. They also come on whenever the air conditioning is on, all the time regardless of temperature.
On the Acura Legend, however, the fans are more complicated. There are two electric fans, but they are two-speed electric fans. They work in a similar way to the "normal" Honda fans, but there are more variations-I will have to read up on their operation and report back on this. I believe there is an ecu involved, complicating matters.
So this may be normal to cycle on and off like yours is doing, bottom line.

 

[msdw24]

Same type of question I have (sort of). This weekend I drove to austin from houston. All the way to Austin my A/C worked great, cold blowing just like normal. I get to Matts El Rancho to have dinner and when I leave the A/C is blowing but only hot air it didn't get cold at all. The next day I don't drive the car. Sunday on my way home it is still blowing just hot air and not getting cold. Then I stop for gas at Eligin and when I start down the road it finnally starts to blow cold and then worked fine all the way to houston.

This morning on the way to work it worked fine. What in the world could be happening? Is this something I need to go get looked at right away?

I don't really know how my cars A/C works so a little help there would be great too. The A/C would blow like normal it just wouldn't blow cold air.

 

[accuratehorn]

94 Legend-two fans, two control units, various sensors and relays. If temp in radiator goes to 184, both fans come on, but on low speed, goes down to 172, off. If temp goes to 194, both fans on high speed, cool down to 184, low speed, 172, off. A/C on-both fans on-low speed, unless temp is high in radiator. Also, engine oil temp is checked, and there are a couple of other features, like turning the A/C off if the water temp gets to 256. See if both fans are on at the same time, if not seek help. You are probably just hearing them cycle from low speed to high speed in hot traffic conditions.

 

[accuratehorn]

msdw24-your A/C is cutting off electrically, because it would not work correctly when it works if all the refrigerant leaked out. Could be a relay, the switch, the low/high pressure switch, or the compressor clutch. Needs to be checked out-if it is the clutch slipping on the hub, it can ruin the compressor.

 

[msdw24]

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[accuratehorn]

Some of the things it could be are not too expensive, like a relay, could cost a hunnert or so part and labor, or you could need a 300-400 clutch or a 600 or 1000 compressor. Only if the clutch is spinning on the hub of the compressor should you avoid using it-the other things it would be fine to use it, so maybe you should get it checked. If you are lucky, a ground wire could be loose or corroded, something really minor. It does happen sometimes.