I am curious about the heater in my 90 Eldorado, when I turn the heater on it blows thru the defroster, is this right? My last two Caddies blew thru the floor vents, what gives?

No that is not right. Defrost is the default mode. You have a vacuum leak. The parking brake release is operated off of the HVAC vacuum as well, so if it does not work then that is likely where the problem lies. If it does, check all the vacuum lines under the dash from the programmer to the air distribution doors. If they are good, check the supply line at the firewall (passenger side). If that is good, follow it back to the reservoir.