Can anyone tell me why the A/C in my wife's '98 JXi conv. will arbitrarily switch from normal discharge out of the dash outlets to discharging through the heater outlet or, other vents, on its own? Sometimes it even seems to deadhead, where you can tell it's pumping out air, but it doesn't discharge anywhere. The car does not have ATC, and manually changing the diverter setting only temporarily corrects the problem. Even then, it shortly reverts back to it's own choice. Any guidance would be greatly appreciated. Thanks.

 

There's a "mode door" inside the guts of the heater-A/C unit that diverts air to where the controls tell it to go. The problem could be the motor that operates that door, or it could be in the control head, or somewhere in between.