theair in my 93 chrysler lebaron only blows out the defrost vent and not the others what might be wrong?

I had a '99 Sebring... May she rest in peace (or pieces?)... I had what sounds like a related issue with mine - and I hope this helps you... Mine only blew out on HIGH - any other setting didn't pump out any air at all... There is a resister (reostat) located above where the passengers feet go and once I replaced it (and I had to do it OFTEN until I finally replaced the fan... who knew?) it worked find. I'm betting that there's a relay that's closed that needs to be opened and it may rely on how much air is circulating. Since she rolled her last mile, I replaced my '99 Sebring (convert) with a '07 Toyota Solara that I've fallen in love with. Sebe (as I call her) had 200k miles and I didn't want to get rid of her as she was my baby... I'm now wishing I did this a long time ago as my Toyo is a much nicer ride..... Hope that helps... peace.