Owners of other A/C systems with similar outside condenser units such as Trane, GE (General Electric), LG, Lennox, Amana, American Standard, Arco, Carrier, Goodman, Bryant, Luxaire, York, Kenmore, Frigidaire, Goldstar, Maytag, and Whirlpool may also find this guide to be useful.

The symptoms of a home air conditioning system that may need a new start capacitor include the inside air handler only blowing room temperature air, the outdoor condenser fan motor won't turn on, or both the outdoor condenser fan motor and compressor won't start.

You may hear an electrical humming sound coming from the condenser unit's fan motor and/or the compressor. It's also common for the top of the condenser near the fan to feel hot.

If your condenser unit has a "dual run/start" capacitor (for both the fan and compressor with three wire terminals), the HVAC system still won't cool the home even with the fan running since the compressor won't be able to start.

The first few steps for replacing the capacitor are to turn off the A/C system at the thermostat inside the house, turn off the A/C breakers in the home's main breaker box, and pull out the fuse block or "handle" outside by the condenser.

Your condenser unit may be equipped with a common breaker switch in the outside power supply box rather than the circuit block/handle as pictured above.

There are several common methods for discharging the dangerous voltage stored in a capacitor.

They include using a screwdriver to short the terminals (possibly dangerous), using a resistor attached to wire leads (safest), and using a motor/bulb or other electrical device attached to wires.

I chose to use a common desk lamp with a 60 watt light bulb attached to two old car stereo wires as my capacitor discharging device.

A multimeter can also be very useful for double checking that the capacitor is really discharged before removing it.

Refer to the owner's manual for your multi meter for the correct settings.

Some newer condenser units are equipped with a "bleed resistor" that will automatically discharge the capacitor after the power supply is removed.

Even in this case, you should still use something to discharge the capacitor just in case.

The access cover is on the side of the condenser that has no air vent openings like the other three sides.

(If your condenser unit is a smaller round unit as commonly used for apartments, condos, townhomes, or small houses, you may be better served by referring to my GE Mars HVAC Condenser Unit Dual Run/Start Capacitor Replacement Guide.)

Once the access panel is moved out of the way, you'll see a small metal shelf filled with wires and electrical components. The round (or possibly oval) device that looks like a large battery, is the capacitor.

A "start" capacitor has two wire terminals while a "dual run/start" capacitor will have three power terminals.

You can usually easily tell the difference between a "start" capacitor, a "run" capacitor and a dual "start/run" capacitor by examining it.

A "start" capacitor will have two electrical terminals that are recessed from the top and usually a black plastic case.

A "run" capacitor will have two terminals that extend out from the top and a silver metal case.

A "dual run" or "dual run/start" capacitor will have three electrical terminals labeled "HERM", "FAN" and "COM" with a silver metal case.

But to be completely sure, I turned the desk lamp on and touched the two car stereo wire leads to the two terminals on the capacitor in both polarity combinations.

Slide the old capacitor out of the metal strap without touching the terminals or other electrical components in the box.

Hopefully you have an HVAC parts supply store or home appliance parts warehouse in your area where you can purchase a replacement capacitor with the same microfarads and voltage rating as the old one.

Alternatively, you could buy a replacement online or possibly from a local A/C repair company at a premium price.

A new A/C condenser capacitor, depending on the type, could range in price from about $10 to around $40 with the most common price being between $25 and $30.

Be sure to bring the old faulty capacitor with you to the parts store for them to verify that they sell you the correct replacement.

If the old capacitor is bulging, deformed or leaking an oily substance, transport it in a box or plastic bag.

Avoid touching the greasy substance if your capacitor developed a leak since older capacitors contain cancer causing chemicals known as PCBs.

Newer capacitors no longer contain PCBs but this also means that they have a limited shelf life.

I had also turned off the breaker switch on the air handler, so I turned that on as well.

(This would be a good time to remove the dust, dirt and debris on the condenser coils since you already have the access panel removed. For more, check out my Rheem Classic HVAC Condenser Coils Cleaning Guide.)

If it works, replace the condenser's electrical access panel.

If the system doesn't turn on or only the inside air handler starts working, double check that every breaker switch and/or fuse block has been turned on and/or replaced.

It may also take a few minutes for your A/C system to start working.

Be patient and don't quickly cycle the thermostat on and off as this may cause damage to the compressor.