Hello,


Whenever I turn on my defrost, I hear a weird noise coming from under the hood, sounds like a clicking noise every few Min's(also seems to draw power). It only happens when I have it set on defrost, if I have it set to panel or floor the sound goes away. I also started to hear a whistle type noise from under the hood at about the same time this problem started.


Any help I can get is much appreciated.

Car info:
95 Contour GL

PS> I am new to the boards so be nice

If you have it set to blow cold air, then the comressor for the AC turns on to dry the air before it is set onto the windshield. As for the noise... more detail. Did you listen with the hood up? Does it get louder or faster with an increase in the fan speed?

Alright, bro, I'll tackle this one. I'll be nicer than some would be, too.

On our cars, when you turn the dial to front defrost, it automatically turns on the A/C compressor to dry the air going across the windshield. This is to remove all that fog you and your girlfriend managed to put there .

The clicking noise is the compressor clutch kicking in. It turns off and on periodically. The whisling noise is the A/C cooling fan. If you look at the radiator assembly, it has two fans. One is controlled by engine temp, and the other is for the A/C. The fans on our cars make a tremendous amount of noise. Sounds like a big Kenworth blower or something.

The reason it draws power like you said is because the A/C compressor is an added load that the engine has to turn. All this is perfectly normal, and not to be worried about.

The things you should worry about are covered under the FAQ and MOD links on the main page.

Now for the soap box:
This feature is an idiot switch sort of thing that all manufacturers are going to nowadays. I hate all these cars that think they are smarter than me. Used to be, if you wanted warm air to thaw out the windshield, you would turn the direction selector to defrost, and turn the temp nob to hot (which it would have been at anyway if it was that cold).

If there was fog on the inside of the windshield, you would push the A/C switch. Very simple. Now they make cars that don't have A/C switches at all. They think that I only want conditioned air coming out of the dash vents or at the windshield. Maybe I want cold air directly on my feet if I have hot feet or something.

Also notice there isn't that little outside/recirculate switch anymore? The only time you can put the HVAC on recirculate is with Max AC.

My point is I don't want to have to deal with the drag of the A/C compressor every time I want warm air on the windshield or want to block out some nasty old pickup spewing unburned hydrocarbons at me.

I want to have the choice, not have the car make the choice for me.

I liked it when cars were stupider than they are now.
What about everybody else?

Sorry. Been wanting to do that for a while.

Peace

Jed

Oh, and welcome to the family. Glad to have you.

Jed

Thank you for the welcome, but I am still not sure the answer you gave me was correct(not trying to sound rude).

More info:(this is with it set to full heat) First this weird defrost noise just recently started(I am almost sure)and it goes off and on every 30 seconds or so. could this really be the AC compressor and be normal? As for the whistle, which also just started, I can hear it 24/7 with or without the defrost on, could this really be the AC fan and also be normal?

Edit: I can hear the whistle with the hood up or down(the sound seems to stay at the same level). As for the clicking noise with the defrost,it is pretty loud and I can feel the car bog down when it goes on, I heard it with the hood up.

Once again I thank you for responding to my help post and the information was much welcomed.

Jed has provided the information you need.

The whistling sound is probably a bearing on its way out. If you are not comfortable inspecting the accessory belt system, take it to a shop.

The extra noise may be your A/C compressor in an impending failure mode. There is an alternative explanation that will require you to open the hood and try to isolate the source of the noise. If the noise is coming from the throttle body are when the A/C compressor engages, you have an idle air control valve that is exhibiting symptoms of "moosing".

Jed,

One correction. Fans are wired in parallel and are two-speed. A/C always forces high speed operation.

You're right, I liked it better when I had to turn on the controls for what I wanted. I'm no dummy...

Steve

Originally posted by draonbreth32:

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I want to have the choice, not have the car make the choice for me.

I liked it when cars were stupider than they are now.
What about everybody else?

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Amen, Amen, Amen..........I've been battling a cooling fan problem for over a year, and many a time I've wanted to get rid of the computer controls on that thing. I wish that when I turned something on, it was on, and when I turned it off, it was off.