Air Conditioning - Outdoor A/C Unit Fan keeps turning slowly, Compressor cannot start

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lscclchan
07-05-09, 10:20 AM
I have a 9-yrs old Trane XE 1200 AC system.

The outdoor unit did not work 2 months ago and I replaced the run capacity and it worked fine for the last 2 months. However, the AC died again last Wednesday night. The symptoms are:

1.) Even though I turn off the thermostat, the fan of the outdoor unit keeps turning slowly.

2.) When i turn on the thermostat the outdoor fan runs at full speed and I can heard a click sound. The compressor cannot start.

3.) No problem with the breaker. It did not trip the breaker.

4.) No fuse in the disconnect switch.

I tried:

1.) Replace another new Run Capacitor

2.) Put a 5-2-1 compressor saver (a potental relay and a start capacitor). I guess it is the hard start kit people talking about..

So does anyone knows any fix for this problem? I don't want to have a technician to replace the compress and it is too expensive. Thanks.


daddyjohn
07-05-09, 11:48 AM
Ohms test the fan motor to see if it's grounded. When you have the fan motor wires disconnected, turn the power on briefly and see if the compressor will start.

lscclchan
07-05-09, 02:52 PM
I disconnected the fan and when I start the AC, I heard that the compressor was giving out low humming noise... so what can it be?


lscclchan
07-05-09, 03:48 PM
I just tried another way...


i disconnected the fan, connected the potential relay and start capacitor (hard start kit) and put the power on again. The compressor gave some noise and sounded like it is running. However, when I set the thermostat to make it start cooling the compressor just shut down...

Then I removed the hard start kit and put the power on again. The compressor made noise again and sounded like running. And again when I turn on the thermostat the compressor stopped...

I am not sure what I should try now...