2003 Lincoln LS V8 3.9 whining noise from behind back seat

[ssurj]

I have a 2003 Lincoln LS V8 with almost 70,000 on it. Whenever I turn on the a/c or heater, there is this annoying loud whining sound that comes from behind the back seat, towards the deck. I still get hot air, and cold air, but the whining is annoying, and has only just started the last month or so. As soon as I turn off the a/c or heater, it stops..thus, I'm assuming it has something to do with that.

***JUST TO CLARIFY*** It's when I turn on the "AUTO" button, to run the heater/ac. But basically, there is no way to run the heater/ac anyways without this coming on. It's a higher pitched whining noise.

Side note: I did notice this morning when i had to use my wipers that there was a similar noise coming from the same general location (Trunk/rear deck). I'm starting to think that maybe it's a motor going bad on me. But what motors are hidden/housed in that area? I'm all about fixing it myself, it's FIGURING it out first that's the pain.

What specifically could this be? Dealer wants to charge me just to look at it....

Your advice is appreciated. Thanks!

[shorod]

Are you absolutely sure the noise is coming from back there, and it's not just a sound reflecting around to make it sound like it's coming from back there?

Does it still make the sound if the car is not moving, but the A/C is on? What about is you turn the blower speed down? With the car not moving and the noise present, climb into the back seat and try to pinpoint the sound. Open the trunk and listen in there.

There is nothing that I can think of specifically located behind the back seat that would be associated with the A/C or wipers. However, there are relays located in the spare tire well with the battery that could be buzzing....

I'm suspecting from your description though that you have something in the blower motor squirrel cage (like a napkin or piece of paper) and it just sounds like it's coming from the rear deck.

-Rod

[Carpoof1]

I know it's kind of late, but I just found this. My guess would be the subwoofers. The factory 6x9 subwoofers are located in the rear deck and the electrical current from the air conditioning system could be interfering. It may be a bad ground or something, but my car used to do this every now and then.

[Drag214]

Originally Posted by Carpoof1

I know it's kind of late, but I just found this. My guess would be the subwoofers. The factory 6x9 subwoofers are located in the rear deck and the electrical current from the air conditioning system could be interfering. It may be a bad ground or something, but my car used to do this every now and then.

Yeah. I agree. Did you recently have an amp installed? when the audio input is not wired properlly or the wires are run to close to a power wire they will pick-up frequencies from your altonator and your amp will amplify them. That would explain that noise you have been hearing. Try setting your amp to only amplify low frequencies. To be sure that is the source of your problem, key on the car (turn the car on but don't start the engine) try useing the assesories. If you don't here the noise, then I'm wright . If you do here the sound then...opcorn:

[clubairth]

Turn off the cooled seats. The fan in the passenger side is what you are hearing. Make sure no lights are on for seats. You can set the seats to automatically follow the DATC. Or you can over ride the automatic climate control and make the seats heat or cool independent from the DATC settings.
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