I didn't see this in the FAQ, so I thought I would share my experience.

BTW, the reason I removed the glovebox was because even with the temp control on cold, there was still a little bit of hot air coming out of the left dash vent. The other 3 dash vents were not experiencing this problem. I suspected a misadjusted temp control cable.

In any case, the glovebox is held in place by two screws and two nuts. The two screws are hidden under little 1-inch square trim pieces that you see when the glovebox door is opened. These trim pieces are easily removed with a small flat-blade screwdriver. Then you can remove the two phillips screws.

The two nuts are hidden at the bottom of the glovebox... you have to look up from the passenger floor to see them. There's one on each side (10 mm).

With the fasteners removed, the glovebox slides out easily.

This allows you to see the temp control cable, which runs from the back right of the temp control box, to the air baffle box (or whatever that thing is) behind the glove box. This cable can be adjusted, and the adjustment is made by turning the cable extender which is in behind the temp control box. In my case, even with the temp control all the way on cold, the cable was still not being extended fully (which allowed a little bit of hot air to pass through). A turn to the adjuster and problem solved.

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Matt L. Cary, NC three '89 740 sedans