Defroster Whistles - No Air Flow

[1999Sahara]

Hey all -

When I flip on the front defroster in my 1999 Sahara, I hear a thud inside the dash and then it whistles. The higher the fan setting the louder it whistles. When the defroster is on, I can't feel any heat coming out of the dash. If I switch to defrost and floor, the whistling stops but I still can't feel any heat from the dash. All of the other AC/Heat settings work fine. A visual inspection of the vacuum lines behind the glove box turns up nothing unusual. Any thoughts before I take it to the stealer?

[Goofatyerservice]

I had the opposite problem -- I couldn't get the defroster OFF.

I'd drive down the highway, turn on my heat, and I'd get heat out of the defroster, none from the regular vents


I'm not kidding:

How'd I fix it? I slowed down. Everytime I let off the gas when this was happening- it worked.

[1999Sahara]

Thanks for the idea but I have the same problem when I'm idling in the driveway.

[b1pig]

it's probablly the door actuator arm(s) on the side of the heater core. there is a story on a "cheap" fix in JP Magazine.

might be on their web page.
www.jpmagazine.com (http://www.jpmagazine.com)

the arms are on the driver's side, so if you look under the dash below the steering column and look towards the middle, then you should see the arms. 3 of em i think.

moving to SWB tech. smile.gif