1986 Cadillac sedan deville is my first car. the A/C doesn't work. Air blows out of the vents but it is not cold. I checked the fuse, that is fine. I don't really know what I'm doing, so any help/advice would be appreciated.

Well you need to post more info. What mode is the climate control in? what is the temp set to? Is the engine warmed up to operating temp? Is the coolant filled to the top of radiator and are the hoses going to the heater warm/hot when engine is running?

did you use the correct type of Freon for the compressor type?

The problem is likely related to a failed air temperature control blend door, it is likely stuck or the electric actuator is defective which is most often caused by a sticking warped blend door in the air ducting. Yo replace these parts requires the entire dash be removed from the car, about a $1000.00 job.

Check to see if you have air to shocks, check air lines for leaks, check pump to see if it is working, check wires for broken wire or if fuse is burnt.

check the heater control valve. sounds to me like the dash control unit that opens and closes the vents may not be functioning properly

on my 99 devillle concours cold air blows from left and back vents but hot air blows from right vents

HAVE THE SYSTEM TESTED BY THE DEALER, THERE SHOULD BE A FAULT CODE. BUT THE MOST LIKELY CAUSE IS THE AMBIENT AIR TEMP SENSOR.

Either Your fan switch is burned out or you blower motor is no good, your blower motor is on the passenger side under the dash. Before you replace any parts you need to check your fuses and relays under your hood and in the car. Usually if your fan switch goes bad you will still get some air blowing thru the vents, so my guess would be blower motor, If its not a blown fuse or relay.

change the thermostat

there,s a chance that your hot-cold air trap is not working