2000 Crown Vic - Strange noise from heater controls?
I have a 2000 Crown Vic I just bought a couple weeks ago. It's the LX package, and still in great shape.
One thing that's come up in the two weeks I've been driving it: Every now and then, seemingly at random times, I get a very high-pitched whine coming from what seems like just under the dash or maybe from behind the radio/heater controls.
It's not the radio - it happens whether the radio is on or off. It definitely has something to do with the heater controls, though, because if, for example, the heat or fan is off, turning it on to vent/floor/defrost will kill the noise. If the heat or fan is on when it starts, switching it off has the same effect. I've yet to notice it happen when the A/C is on.
It's totally random, and I can't figure out if there's a catalyst or not. It seems that it might happen one time one day for maybe 5 or 10 seconds, and then not happen for three days. Then it will come and go steadily over the course of a day or two for as little as 5 or 10 seconds but sometimes lasts a minute or two, then not happen again for a week.
The guy who owned the car before me said he though it was the flapper in the air ducts that switches the air from vent to floor to defrost had a bad seal or something, but it doesn't sound like that kind of noise to me - vehicle speed plays no part in the sound of the noise, and if it were leaking air, the inrush or the fan speed would play a definite part in how it sounds.
To me it sounds more like an electronic noise, maybe like the seat-belt dinger or lights on/car off bell would sound if it were shorting out against something intermittently. But, again, bumps in the road or taking corners isn't what causes it.
I'm just wondering if anybody's had a similar experience or knows someone who has, or maybe saw a bulletin posted somewhere that describes the problem and a solution. I don't want to kill a Saturday ripping my dash apart to go on a wild goose chase, or god forbid, pay a mechanic umpteen hundred dollars to do it for me.