AC help

So my 93 JGC has a/c and when turned on the lines are cold the compressor is on, but no cold air comes through the vents is there an electric relay somewhere? can it be repaired if this is the case. The freon tank is full and there are no leaks?

Thanks in advance for the help.

If there is no cold air coming out, then it could be a problem with the fan that accelerates the air out of the vents. It may be burned out or somthing. I dont know how to replace or fix it, but I think that's what the problem is.