If your air conditioner won't run when you first turn it on in the spring, there might be a problem with the power supply. You may need to call an air conditioning repair company for help, especially since it's a good idea to have your AC serviced before you turn it on for the summer. Here are some things that might keep your AC from turning on.
The Capacitor Is Dead
A bad capacitor can keep the condenser fan and compressor from starting up. It may look like the fan and compressor are dead too, but the repair technician can check them with a multimeter to verify the parts are still okay. If the problem is narrowed down to the capacitor, the air conditioning repair technician can replace the capacitor with a new one, and then power will be restored to the parts in the condenser.
A bad capacitor is a common AC problem, so your repair technician may check it first when the AC won't come on. The capacitor is a fairly inexpensive part when compared to the compressor and fan motor, so it's one of the more affordable parts to replace. You'll want to replace it as soon as it goes bad or the fan motor or compressor may struggle to start without it and burn out.
The Disconnect Fuse Is Bad
The air conditioning repair technician also has to consider if the unit is getting power from the electrical panel. They may check the circuit breaker to make sure it's on, and then they may check the disconnect box to see if the fuses are good.
Power goes from the electrical panel to the disconnect box and then to the side of the condenser to the contactor. If the repair technician tests the wire where it comes in the condenser and it has power, the circuit breaker and disconnect fuses can be ruled out as the source of the problem.
The Thermostat Wire Is Bad
Your condenser is triggered to turn on by the thermostat. There's a wire that leads to the contactor in the condenser that triggers the contactor to send energy to the capacitor and compressor so the AC kicks on. If the wire is bad, or if the thermostat is having issues, the condenser may never get the signal to turn on.
The air conditioning repair technician can visually inspect the wire to see if it's damaged, as this might happen if mice gnaw on the wires. The technician can also test the wire and contactor to see if power is coming in the condenser and where it's being lost.