a/c makes hissing noise, doesnt blow cold
 

a couple days earlier my a/c worked fine, then it wasnt cold at all anymore and there was a hissing noise coming from the center vent.

the blower works and so does the heater.

could the hissing be a vacuum leak? how would a vacuum leak in the a/c affect its performance?
could this just mean im out of refridgerant?

thanks

Grdenko,

Look at the 3rd tread of this forum : your answer is just right there!
Couldn't be repeated enough!

Danny

i did, several times. nothing about a hissing a/c.

Your A/C has leaked out its freon. The hissing sound comes when the freonis below a certain level. The fact that it is not cooling is a tell tale sign that the freon is low. Unfortunately you have R12....If you had 134a, it'd be no big deal, just go to target/walmart get a few cans and charge it back up. As it stands, you'll need to find a shop, get the leak scoped , fixed, and then recharged. If its the dreaded evaporator core, you may as well just trash the car and get another. A 91 300E ain't worth the $2500 MINIMUM that it'll take to repair the A/C. Heck it's probably not worth(Blue Book) the $250 it'll cost to get the leak diagnosed........ :(