This air conditioning repair article explains procedures for the diagnosis and repair of hard-starting air conditioning compressors. If your air conditioner or heat pump compressor motor won't start or has trouble starting, humming at start-up for example, it may be damaged and at or near end of life. But a common repair performed to try to get such motors running and to keep them in use longer is the installation of an air conditioner or heat pump "hard start" kit - a start capacitor or a start/run capacitor that helps get the motor spinning. First it's useful to diagnose the cause of the compressor's hard-starting trouble. Continue reading at CAPACITORS for HARD STARTING MOTORS or select a topic from the More Reading links or topic ARTICLE INDEX shown below. I have a 15 year old Bryant Central Air unit in my house. Yesterday it stopped working. Here is what I have checked. The breaker in the basement is not tripped. The furnace works fine from the thermostat.

The blower downstairs by the furnace runs when AC is on and blows room temp air into the house, but the fan on the compressor is not spinning. The fan on the compressor does spin freely when I manually spin it with a stick. Checked for fuses in the outside box. There are no fuses outside, only an on/off pull thingy with two metal plates that you have to turn upside down to turn off.air conditioner leaking water into room The capacitor is not flat on top, but far less rounded then any of the examples of blown AC dual capacitors I've seen on youtube.average cost of new hvac unit I get 220v in on the contactor.car ac repair in san jose I get 220v out on the contactor. I get 24v from the thermostat. When the air is on at the thermostat the contactor solenoid is in, when the air is off it is out.

When the air is on at the thermostat I hear a buzz coming from the outside compressor but I can't tell what the source of the buzz is. If I push the solenoid in when the AC is off, the compressor does not start up and the fan does not spin, I just hear the buzz. If I wait by the compressor outside for a few seconds while the AC is on there's another buzz sound that goes off for about 3 seconds then stops. From listening to the AC when it was working this is the buzz sound that goes off before the compressor and fan usually kick in. After leaving the non-functioning unit on for a few minutes while I diagnosed I noticed that the metal on top of the compressor fan motor was VERY hot to the touch. It cooled after I turned the AC off. I'm thinking the fan motor on the compressor is dead or the capacitor is bad. Is there a way to check the capacitor and the fan motor while they're still in the unit? With the power off of course. Does anyone think it's something else? Do I have to buy the overpriced ($485 for the manufacturer fan motor and $200 for the dual capacitor) replacement part from the manufacturer or can I use a third party manufacturer?

Any other help would be appreciated. As much as I'd love to bring an HVAC guy in here I just can't afford it. Either I go without AC, or I fix it myself. EDIT: With the AC on I manually spun up the fan on the compressor and the fan started spinning and the AC unit fired up. I ended up pulling the capacitor and testing it with my ohm meter. I could have easily gone to the local HVAC supply, purchased a new capacitor for $30 and installed it myself. But, because I also wanted to have the pressure tested, I called in the guy who installed my furnace. He affirmed that I "did good", it was the capacitor. And because I had done most of the diagnostic work, he cut me a good deal. In the end, the most important bit, on a 95 degree day when the humidity is 70%, a happy wife is a blissful life. Just for future reference. The Compressor has 2 winding's, a Run winding and a Start winding, the Common terminal is the point at which both of the compressor winding's connect, thus the "Common" designation.