Unit powers up, fans run, no compressor start

Manually (carefully) activate the contactor relay to see if you can get the compressor and condenser fan to operate. Make sure your fuses and circuit breakers are supplying power to the unit.

And you have what appears to be run and start capacitors in unit. Make sure that they are operational lsst unit will not start or run.

Dose compressor fell too hot ? There could be several things wrong. First you will need to get out your Volt meter to make all test. With unit calling for freeze cycle the condenser fan and compressor should be running. Check at the compressor to make sure your getting power to the over load switch and then through it to compressor. if not then check to see if compressor is to hot and has the switch open> If so then unplug unit to let compressor cool down so switch will close. when switch closes plug unit back up and start up unit check to see it compressor starts if so then you will need to see what is causing compressor to over heat. could be dirty condenser, low charge, fan dropping out, Bad compressor.

If the fan on the backside is not spinning it could be a bad fan-motor. When the fan runs the compressor should run as well. If the compressor is not running the fan should not be running either, so you should unplug it for about an hour, then plug it back in and see if the compressor unit starts up. If it doesn't, it is probably something wrong in the control circuit for the compressor. It could be the thermostat (check that it is set correctly). If the compressor starts up but the fan does not run, it is most likely a bad fan motor or bad wire leading to the fan motor.

It may cause it to shut down if it's a safety thing, but it sounds like the compressor's faulty to me.

Problem #1:Outdoor condensing fan motor has stopped running. This problem could be caused by a bad motor run capacitor. If your motor capacitor is not the problem, then more than likely you need a new motor. Is the fan blade tight, stiff or hard to turn? If the fan blade is hard to turn then you probably need a new motor. Problem #2: Air conditioner compressor will not start. When power is applied to the air conditioning outdoor unit the fan starts, but you hear a sound like the compressor is trying to start, "UGGG"..., for about 5 to 10 seconds and then all you hear is the outdoor condenser fan run. The compressor is locked and will not start. What is happening is the compressor is trying to start, but because the compressor motor is locked it tries to start for a few seconds and then because of the high amperage being drawn goes off on internal overload. The internal overload protects the compressor windings from overheating and burning up. I see this many times during the start of the air conditioning season. Some compressors just have a hard time starting after sitting all winter long. Some compressors are locked up so bad that I can not start them and must tell my customer that they need a new compressor . Many times I can get the compressor started again without having to buy a new compressor or new air conditioning system by using the device known as a "Super-Boost." I keep two or three of these on the truck. They have saved many of my customers from having to buy new air conditioning compressor. Another good device is called a "5-2-1" kit.

If the fan is not running is the compressor not running also...if neither is running the possible reasons are 1..no power to outside unit...2..bad contactor on outside unit.is this buzzing if it is this indicates no power...3 bad capacitor,do both compressor and fan humm then quit humming and hum some more...4 high pressure switch has shut unit down because fan wasnt running if compressor was running but not fan....if your unit has this there will be a manual reset button where the lines come out of unit...if compressor was running and fan was not...1 bad fan...2 bad capacitor.. if you do not have any electrical knowhow i would recommend calling a hvac tech to come and fix unit...Thanks

Thanks for your detailed information. But solution is very simple. The compressor contactor in out door unit. Struck. And hence, when you power on, without indoor commanding, the out door starts running.

Replace same type Contactor relay (In out door unit) immediately. Hope, it's helpful.

Verify the compressor is running. If it is then you need to get the refrigerant charge checked. If it isn't, check for an overload that may need to be reset and use an ohmmeter to check the compressor motor winding. The fan and compressor run off of the same contactor so I would think it has power to it. Does the fan and the compressor use the same capacitor? If they do and you haven't replaced it yet then try that first.

if the compressor is starting there will be a very small dimming in the house lights,if you go outside to the unit and start it from the outside disconnect when the compressor starts you will hear a whine type noise coming from the outside condenser unit that is the hermetic compressor motor operating,no cold air can be a number of issues,low on refrigerant(not likely on the new sealed systems) a bad motor start/run capacitor(quite likely) a bad contactor on the outside unit that supplies power to the compressor,one leg of the 240volts that supplies the compressor power,the fan will run on 120 volts,but the compressor needs 240 volts check the fuses.breaker in the power panel

Is the outside unit running? if so can you feel warmer than outside air blowing from outside fan? If not your system may have a leak and pressures low. You can also check the piping to and from the unit larger one should be cold small one should be warm