Air conditioner hyundai tuscon will not engage the clutch

The radiator fan should turn on when the a/c clutch engages as this is designed to increase the cooling of the engine as the a/c increases the engine loading. But the compressor clutch should stay engaged as long as there is need for cooling, and disengage/re-engage as the temperature control calls for cool air. The radiator fan will shut off IF the engine temperature is cool enough to do so, as it is regulated by heat, as well as the A/c override.

If your air conditioning is not cooling the car and the clutch is simply disengaging prematurely, have the temperature control and relay checked for proper operation. Also have the refrigerant level checked to assure there is adequate refrigerant in the system and no leaks. My first bet would be the relay or the thermostatic temperature control under the dash.

David;
In older vehicles these controls were vacuum controlled. Now most are electrical. My first check would be the accessory fuses

have an a/c mechanic look at the system as there are 2 switches in the system that control the compressor operation. controls over pressure of the system and the other covers low gas in the system. both control the compressor relay that engages the clutch of the compressor. Check for a fuse problem in the power line to the a/c switch in the dash

The AC will come on when the DEFROST is on.

The AC Compressor has a Clutch on the front. You can see if it is engaged or disengaged

Looks like you checked all the things that need to be checked except "one." Sounds stupid, but did you check your temp switch on you dash to make sure it is the air conditioner you want to run instead of the heater? Sometimes, many forget this one simple check and can't figure out why the air conditioner won't engage.

Think about this:
Can you supply voltage to the clutch to engage it? Remove the connector and use wire to directly energize the clutch. The only thing that I'm unsure of is whether it is 12 volts.
Gary

check into the blower motor

Check for a fuse that indicates radio and replace it if it's burnt through or melted or discolored. The Buicks have dash controls that require expensive repairs sometimes to get the temperature controls to work so some people jump around the controls by installing a separate toggle switch that directly turns the AC unit off and on for 92 through 94 Buicks. Any AC shop can install the bypass wires.

Check the AC magnetic clutch relay, it may be sticking open. Bypass it (located under the hood) and see if the system cools down, if not you have other problems.

looks like fuse # 8 "heater control relay- ac clutch relay-cooling fan" fuse runs the 12 volt side " black and yellow stripe wire " pcm or ecm runs the ground side "red -blue stripe wire"- what else do you need?