I just got a '91 240 wagon, and noticed that when I press the defrost button, very little air comes out of the vents near the windshield. The heater works fine, as you would expect in a Scandinavian auto, but the inability to defrost the windshield is a little disappointing. Interestingly, the floor heat button, which is located right next to the defrost button, works fine. I plan on checking fuses, but I would be surprised if that is the problem (wouldn't the floor heat and defrost buttons run on the same circuit? Do these buttons even require electricity, i.e are they mechanical?).

Has anyone had this problem? Recommendations? Haynes manual is useless, so I thought I'd ask for advice before venturing into the dashboard. Thanks in advance.

Eric