heating question

[MJ86YJ90]

so I have hot heat when i put the slider to heat and cool air when its on cool. But its always on defrost even if i slide the slider to off. The blower selector works too. I have searched and checked every vacume line 5 or 6 times and find nothing. is there another problem that is a usual suspect? thanks

[Eagle]

The heater control are operated by vacuum, and the default position when there's a vacuum leak is defrost.

 

The usual place for the leak is the tube or tubes leading under the battery box to the vacuum canister mounted behind the front bumper on the passenger side (variously referred to as the "softball" if you have the round one or the "blimp" if you have the oblong one).

[Pete M]

what he said.

 

did you find anything yet?