Ac on my 2006 Kia Optima is blowing hot air full of freon what should I check first

Buy freon at partstore n try rechargn..easy ta du. Watch for leaks n keep condensor clean thats by the radiator

Usually a sign of low freon or a blend door problem. If the system is full of freon, I would check the blend doors under the dash.

My lincoln had the same issue, first it was the A/C compressor (original). I replaced it with another one (used) and worked for 1 month. Then back to hot air. "A/C experts" told me the compressor was out again. I took it to a Mexican auto shop, old building where the guy works alone and to my surprise...HE FOUND THE PROBLEM!! There was no freon leaks, the lines were freezing cold inside the motor, checked freon>>full. He then checked the filter. This filter is on the end of the line where it is crimped that allows the freon to flow thru. Im no mechanic so explaining what it is, forgive me. I can only show you...the line is silver ad in front of you by the radiator, and its the same tube that goes to where you plug it to add freon. There is a filter that was clogged up and prevented the freon from flowing. He removed all the freon, vacuumed out the system/line, and replaced the filter for less that $3.00. Added freon and his cost was $80.00. Thank God for honest people who work hard for a living. I buy the parts, he replaces and I continue to give him my business. Other expensive auto shops with fancy buildings/prices My Lincoln Mark LT now blows arctic cold air!!!

You'll need to have someone check the circuit - could be a bad a/c clutch, relay, or short in the wiring.

my ac turnsn but blows only hot air , it doesnt need freon. i know water is leakin under the drivers foot petal. mechanic says must have a shortage help

And the freon is full is it cycling? yes to this, to then your expansion valve is non op

you will have to get a dye injected into the system or have it checked witha freon probe

2006 Kia Sorento EX. I had this same problem. It started after I had the ac compressor replaced. At first it was intermittent, it would blow cold and then blow hot, blow cold then blow hot again until it just started blowing hot. Turned out it was the AC relay switch in the fuse box under the hood, I swap it out with the horn relay switch (they were the same type relay switch) the ac has been working fine ever since and the horn also works even with the bad relay switch. Go figure?

Absolutely not!  Never attempt to recharge from the high side. Recharging from the high side is extremely dangerous and could do harm to both you and the car.  If the low side pressure is only 10psi, you are low on refrigerant.  Most cars require 20psi to operate the compressor and should never fill to more than 40-45psi unless recommended by the manufacturer.  I'd re-check the pressure readings.  It's possible that instead of charging the system, while hooking up the hose, you've let freon escape, accounting for the hissing noise and the low pressure reading.  When recharging the AC system, it's important to have the car running and have the AC on high.  It's possible, you didn't have a good connection to the low side which also would account for the escaping refrigerant.  I hope this answers your question.  I'd try to recharge the system again on the low side, making sure the connection is good both at the low side valve and on the can of refrigerant.  Best of luck.
Greg

Take the car for a scan it is ob2 compliant.

there must be a fault in the fuse and relays.