In case you didn't here's a little info (based on my '83). When you push the selector switch to any position but off, two things are supposed to happen. One is that the blower motor starts and the other is that vacuum is supposed to be supplied to the various doors that direct air flow.
If the fuse on the bottom of the blower motor is blown neither of these things will happen. This fuse is fed directly from a fusible link so there may be a problem with that. If the blower motor runs and no air comes out, the problem is probably no vacuum and you will need to trace the vacuum lines starting with the vacuum tank located next to the underhood light.
Hope this helped.
> i own a 81zx.
> nothing comes out of the vents (not even
> any suggestions?