Posted on Leave a comment

Question: Do I Really Need a New AC Unit?

happy ac

Question: My HVAC contractor said that I need a new air conditioning system. I was not home for him to show me why I need a new system. Is there any way that I can test and make sure that I really need a new air conditioning system? Do I really need a new air conditioning system?

Answer: Yes! We have a YouTube video made by AC Service Tech LLC that explains how to test and make sure that you need a new unit or not.  I have listed the step-by-step troubleshooting steps and tests below if you do not want to watch the video.  A multimeter is required for testing and troubleshooting the unit. We sell a really good multimeter on the following page. Please click here if you are interested in the multimeter that we sell.

Here are the steps in troubleshooting if you do not want to watch the 6-minute video. Many of the steps below involve working with high voltage electricity in testing with a multimeter. If you are uncomfortable in working with live electricity then I would recommend leaving this to a professional. Bodily Injury or death can occur if mistakes are made!

  1. Arrive at the unit and pull the disconnect to disconnect power to the unit.
  2. Test the disconnect with a multimeter set to “Volts AC” to make sure power is getting to the disconnect. You should have between 210 to 250 volts at the disconnect. Always make sure you are careful to not get grounded out or shocked.
  3. Take the control panel cover off the AC unit.
  4. Plug the disconnect back in and test between L1 and L2 at the contactor to make sure that the wires that come from the disconnect are supplying 220 volts to the contactor.
  5. Push in on the contactor with an insulated screwdriver to see if the compressor or fan turns on.
  6. In the video, the fan turns on when the contactor is pushed in, but the compressor is not coming on.
  7. Use the Amprobe multimeter to see what the amp draw is on the compressor when the contactor plunger is pressed in.
  8. In the video, the compressor is running high amperage when it tries to start over 60 amps and the compressor will not start.  This shows that the compressor is locked up and that the compressor has a major problem.  The problem could be a bad or weak capacitor, broken or burnt wires, grounded out, or open compressor windings. We will need to test to see where the problem is located with the compressor.
  9. Turn the power off to the unit at the disconnect and make sure the high voltage power is off. Disconnect the wires off the capacitor and test the capacitor with a capacitor tester to make sure that the capacitor is in good condition. If the capacitor is bad replace it.
  10. Disconnect the Start, Run, and common compressor wires off the contactor and capacitor. Test to see the ohm readings between the wires and test to see if the compressor windings are grounding out. If the ohm readings are not right or if the compressor is grounding out then yes, you will need a new unit or compressor.
  11. In the video, two connections on the compressor are burned completely off and all the refrigerant has escaped. Yes, you would need a new unit or compressor in this case. If you have any questions please email us anytime at
  12. We would love to try and help you and earn your business!

You Can Search Our Site for More Troubleshooting Problems, Heating, Air Conditioning Parts and Supplies in the Google Search Box Below:

Leave a Reply

Your email address will not be published.