s14 heater/ac problems-fan rattling, & doesn't work on 4...

[dosborn]

i've got some pretty bad heating/ac issues on my 95 240... first the darn thing doesn't blow on anything except 4. if i'm driving down the road, and i turn off the recirculate button, i can get airflow through the vents, but once i turn the recirculate button on, i get nothing. also, when it's blowing on 4, the thing is EXTREMELY loud because of a rattling coming from under the right hand side of the dash... any idea what my problem might be? i've been lurking on these forums for quite some time, and you guys seem to know more about these cars than my freakin mechanic, lol...