there is a whistling noise coming from the passenger side of my dash when the a/c or fan is on. Anybody experience this??

 

Same here, does it whistle when the ac is off? Mines does. sounds really low cant really hear from outside but inside its more noticable?

 

does it increase in volume when you push the gas? if it does your alternator or Pulleys are on it ways out happened to me !

 

You can't hear it outside of the car. It happens with the a/c or the fan. I think I'm going to take the glove compartment off and see if I can find it.

 

you have to tighten your alternator belt...

when you turn on your ac your alternator is working more. and the belt is slipping....so tighten it and you'll be fine.

 

I get kind of a hissing/whistling noise under the dash on my pass side too, so do you think its just the belt on the alternator? it doesn't really sound like a loose belt to me, but i could be wrong...

 

If it is a steampipe kind of wwwwssshshshhhhh..... then it goes away, usually happens when you first turn on the a/c, that is normal. It is the expansion valve releasing preasure into the condensor coil behind the dash. Don't worry, it is normal... If it is more of a whistling sound that keeps going continuously when the fan is on, you might have some debris in the air channels or control diaphrams behind the "squirl cage" fan in the dash... that is not normal, and should be checked.

Let us know, good luck.

 

tighten it more...

 

I don't think it's a belt bro... but hey, I could be wrong. Not there, couldn't say for sure.

 

mine does the same thing... it def. sounds like its under the dash and only happens when the a/c is on

 

If your a/c is working, don't worry... I am thinking it is what I described... kind of a steam pipe sound... Mine only does it when it is first turned on on mid temporate days. If you hear a fluid buble-like sound after turning it off, that usually means the system has a little air in it and needs to be serviced. But, I don't think that is it.

 

I had the same whistling and once summer hit and I was forced to use my AC the alternator went out. Didn't know the connection.

 

I think I have something else because mine does it with the fan or a/c

 

Interesting.. here's a scenario I'm having with my 99 3.0 CL...

During the summer when I used my A/C i would hear a whistling / squeaking noise coming from the passenger side of my dashboard. I opened up my hood and saw that my A/C compressor was right in that area. Thinking it was the A/C belt I just went to the local Auto Zone and got some belt dressing and went at the A/C belt. I *thought* it helped, but then the next time i went to go use the A/C again, I heard the same noise ---- probably because I couldn't hear the noise from outside the car.

So anyway, I ignored it for a couple weeks and then when I started my car one day, the voltage indicator light on the dashboard came on and stayed solid. It did not go out until I started the car again. Failing to make a connection, and seeing how I was able to start the car without any problem whatsoever, I figured that the battery was fine and maybe it was a false indication. Until I drove home tonight, that is. All of my lights (Interior, Headlights, Tail Lights, etc..) got dim and bright and dim and bright.. almost like someone playing with your interior light dimmer switch.. only for the entire car. It would do that for only 5-10 seconds at a time. But at intervals of 3-4 minutes. Making my way onto the uphill onramp on my way home tonight, I pushed the gas to accelerate to highway speed. The overdrive kicked in. And when the OD kicked in.. wow. My headlights and everything got as bright as my highbeams.

I'm not sure what Exactly this is. Not sure if it's a belt, or the regulator in the alternator. Would hate to spend $150 for an alternator if it is just a belt fix or something like that. I need to get this problem fixed ASAP though, before it blows out my wiring harness or something. Any help would be greatly appreciated.

 

to check if it's your alternator: while the car is running, disconnect the positive batt. cable... if the alternator is working properly, the car will stay on, if not, it will shut off within a few seconds of disconnecting the cable. otherwise possibly a bad ground?

oh yeah next time start a new thread

 

The a/c hissing is a completely different issue than the alternator. I've recently replaced my alternator due to a bad regulator, smoked that motha. My a/c girgles and hisses when the compressor cycles off. Blows perfectly cold to desired temp though when it cycles off, I hear the girgling-hissing sound.I still beleive it is a harmless side-effect of the temporate weather. If it were problematic, I would have it checked, but I checked it when summer started and it was fine with correct preasures.

Anywho, To the dimming lights, definately alternator. Especially if it is whinning.