I have a vax. Pet performance when in use it blow a lot of cold air out any ideas what up with it pls

If your vehicle's air conditioning system intermittently switches from blowing cold air to hot air, there could be a few possible causes for this issue. Here are some potential reasons:
1. Low refrigerant levels: Insufficient refrigerant can lead to inconsistent cooling performance. When the refrigerant level drops, the system may blow cold air initially but eventually switch to blowing hot air. This could be due to a refrigerant leak or a problem with the AC system's components. A professional AC service technician can check the refrigerant levels and locate any potential leaks.
2. Faulty blend door actuator: The blend door actuator is responsible for directing airflow through different vents. If the blend door actuator malfunctions or gets stuck, it may cause uneven airflow distribution, resulting in cold air on one side and hot air on the other. Replacing the faulty actuator should resolve the issue.
3. Control module or sensor malfunction: The AC system relies on various sensors and control modules to regulate temperature and airflow. If any of these components malfunction, it can cause erratic cooling behavior. A diagnostic scan by a qualified technician can identify any faulty sensors or control modules that need to be repaired or replaced.
4. Electrical or wiring issue: In some cases, electrical or wiring problems can cause intermittent AC issues. Loose connections, damaged wires, or faulty relays can disrupt the proper functioning of the AC system, leading to inconsistent cooling performance. A thorough inspection of the electrical system by a professional is necessary to identify and resolve any wiring issues.
Given the complexity of diagnosing and repairing automotive AC systems, it is recommended to take your vehicle to a qualified mechanic or AC specialist. They have the necessary tools, knowledge, and experience to diagnose the specific issue and perform the required repairs to restore consistent cooling performance in your truck.

Strip the machine down and replace the motor cleaning the airways and filters as you go.

You probably replace the wrong switch. I believe the high pressure switch is mounted in the back of the compressor. Pull the plug and jump it. If it works, replace the switch. I don't recommend you leave the jumper in the plug. If it the A/C pressure is to high, you could blow lines and such. Costing you a lot of money.

if the ac system is very strong and there a lot moisture in the air the a'c evaporator core will freeze up and stop air flow threw the cold core only use the recuiculation part to cool the car down about 5-10 min the turn the recuit off

check to see if your cooling fans are working because when they dont work, your air will blow nice and cold when driving but will be hot air when stopped in traffic.

What is a pet****? If you mean petcock, it is on lower drivers side.

have you checked your coolant? that might be why its blowing cold air

Start the vehcle and let it warm up then set all the controls to heater? Then turn off the car. Use the remote start to start the vehicle and check the controls are still set to heat mode.

This is just an idea, but if the a/c is working good, it may be the relay that changes your heater from hot to cold....give it a shot..just an idea....Please leave a good ratin, it is very important to me...

could be anything from low refrigerant to bad compressor cooling fan or air distribution system. if you never have worked on a c i would recommend taking it to a professional