The car air conditioner is turned on to the coldest level, but it still blows very hot warm air. I checked and found that the solenoid valve from the engine water tank to the warm air water tank is op

First find the ground wire of the solenoid valve, plug in the plug, and connect the ground wire directly. If the solenoid valve can be closed and hot air no longer comes out, it means that the heating and cooling adjustment signal is sent to the air conditioning panel, which controls the solenoid. If the valve is grounded, check whether the air-conditioning panel can receive the heating and cooling adjustment signal. In addition, how do you determine that the 11V power supply of the solenoid valve is virtual?