Your air conditioner condenser has a contactor in it that controls the flow of electricity. It's a small part that can go bad, and when it does, your AC will malfunction. Here's how a contactor works, why a contactor goes bad, and how a bad contactor is replaced.
The Job Of An Air Conditioner Contactor
Your AC parts need electricity intermittently. When the thermostat turns the equipment on, the contactor opens to let electricity flow to a part that needs to start up.
When it's time for the AC to shut down, the thermostat signals the contactor to close the flow of electricity to the part. A contactor has the important role of supplying electricity to parts in your condenser so your AC can turn on and off and cool down your home.
The Signs The Condenser Contactor Is Bad
A contactor can wear out with age. It might also get clogged with dirt. The condenser contactor is outside, so it can get dirty or get blocked with bugs or other debris.
Your AC may operate erratically when the contactor is going bad. The contactor might also get stuck in the on position and not turn off when it gets a signal from the thermostat. The contactor could also get stuck in the off position and not turn on, and in that case, your AC may not be able to start or put out cool air.
If your AC won't start up or shut down, the air conditioning repair technician considers a bad contactor as a possible cause. There might also be a clicking or humming noise coming from the condenser that provides a clue the contactor is bad.
The Steps For Replacing The Contactor
The condenser contactor is located behind the service panel of the condenser. When the air conditioning repair technician removes the panel, the contactor is in plain sight and can be reached easily. Several wires attach to the contactor, and it's important to attach the wires to the same points in the new contactor or your AC may not work.
The repair technician can remove the old contactor, secure the new contactor with screws, and then hook up all the wiring. The technician might leave the wires connected to the old contactor until the new one is mounted so the wires can be moved one at a time to ensure accuracy.
A malfunctioning contactor may not always need to be replaced. If the part is dirty, the repair technician might get it working again by cleaning it. The air conditioning repair technician can test the contactor with a multimeter to see if it is bad and needs to be replaced. However, the technician might be able to tell by looking that the contactor is bad if it's melted or has other obvious damage.