Air Conditioning - Help troubleshooting No cooling problem

Recently moved into an eight year old home, with a Bryant 561C central AC. Worked fine the first time we tried it, however to day when we tried to turn it on the compressor fan would not go on. It would just make a buzzing sound like the motor was trying to activate. I was able to rotate the fan blade to see if the shaft was frozen and after a couple of tries the fan slowly started to spin. It would not spin at full speed and seemed to cycle between low and high speeds, the compressor did never turn on (so no cooling was actually taking place). I checked for power on both legs of the supply line and the thermostat was activating the contactor.:wall: Any troubleshooting suggestions would be appreciated.

It sounds like a contactor problem. If the fan started running and stayed running I would have said capacitor first...

Just because the contactor lets voltage pass through it does not mean that enough ampreage will pass through it to operate the components properly. I would visually check the components for burn marks, bulging, caps blown off, etc.

Most contactors are made so that you can activate them manually with an insulated screwdriver. Many times the extra pressure you put on it will make the difference and everything will kick right on. (Not recommended...)

If you have a combined fan/compressor capacitor with three terminals that may also be the problem. Since both fan and compressor is acting funny..i.e. fan starts to run but slows down (as compressor is trying to start) then starts running faster as compressor ceases to try and start.. Seems like the breaker would trip about that time though...

When I get into that stage I usually replace the contactor and both capacitors. It's not that expensive and if one is out or going out the others might not be far behind.

The contactor is definately pitted and the capacitor is a combo fan/compressor. The GE motor placard doesn't give a start-up amperage rating and since it won't start on its own I can't really check amperage draw. There are no obvious burn marks and the capacitor isn't bulging or leaking. I'll try cleaning the contactor will a point file first to see if that may be the problem since there are no suppliers open on weekends in the hick area I now live in.

The problem was the capacitor. It was so perfectly bulged up at the top that at first it looked like it was manufactured that way. $30 part sure beats a call to a HVAC repair shop:thumbup: :thumbup: :thumbup: