Ac pump will not engage - 2003 Kia Sorento

check blend door. will blow hot even though lines are cold

if air con is not working it could be the clutch in the ac pump, if you dont use the air con much or use it alot you can either have a seized clutch or a work clutch, without the clutch engaging the pump will not work and not flow around the system, when ac is engaged the idle on the engine will drop slightly.

AC on the fritz. When the AC clutch engages, it robs a lot of engine power. When you have your heater control on defrost, it engages the AC to dry the air so your windshield doesn't fog. Try unplugging the wiring harness going to the AC pump and see if that helps.

on the Ac system is a low pressure switch ,sounds like its faulty so fit a pull or flick switch from ignition supply and run this direct to the pump

first thing is always check for any fuses that may control it. if the fuses are all good, then check to see if the clutch (on the front of the compressor pump) is engaging when it's turned on? if not then it's low on freon. It has to have a minimum pressure in the system for the clutch to drive the compressor so the compressor doesn't burn up. If the clutch does try to engage but doesn't fully engage, (slips) then the clutch on the pump is bad.

It may not be a control unit issue. Be sure to check all fuses. You may have a pressure switch issue. There are at least 2 pressure switches located in the engine compartment. One is usually located on the back of the ac pump and there is usually one on the passenger side near the firewall on one of the aluminum ac lines. You can simply unplug the one by the firewall and take a paper clip and unfold it and use it for a jumper on the connector. Put one end of the clip in one side of the connector (the end of the connector that plugs into the switch) and the other end of the clip into the other side of the connector. Start your Tahoe and turn the ac on and if the ac pump is turning with the ac clutch engaged that means that you either have a bad switch or your are low on refrigerant. Feel the aluminum ac lines and see if they are getting cold. If so I would suspect a bad pressure switch. You can remove the paper clip while the vehicle is running and put it back in if you are not sure if the ac clutch is engaged. It should make a clicking noise when it engages and disengages. It is very simple to replace that switch. Simply unscrew it and screw the new one in and plug it in. It will hiss just a little when you remove and install so be quick. It will stop when you remove the old one and will hiss again a little when installing the new one. The switch on the back of the pump is not so easy. The refrigerant needs to be evacuated from the system before it can be replaced.

They most likely did not refill the freon in the ac system.

The ac pump has a clutch coil,it is activated with the ac button,and then the middle of the pulley will turn this is the clutch,it only turns with the ac on,then when it is turned off,the pulley just turns not the whole clutch,so this is normal.

is your AC pump turning? if not that couild kill an engine...theere is also a switch-usually on the pump- that controls engine speed when ac is on and pump kicks in, this might be faulty...problem usually confined two these two scenarios......hope this helps

if you by passed the relay and clutch engaged then this shows that pump works ??but was it getting cold on and around the restrictor valve where the pipes enter the cab is normally a valve block but american monsters use a valve in the pipe for cooling and if its not getting cold their or blowing cold inside cab then system needs re-gassing with R 134 gas if its an older system with R 12 gas then it will need to have adaptors fitted to valve connections and refilled with R134 gas.The main cause of A/C system loosing gas is porosity in the rubber flexible pipes also the back seal on the pump.Or just regass and put a leak stopper in the system