As others have suggested. You can check to see if the outdoor unit has
220 VAC. You can also check to see if the contactor is getting the 24
VAC signal, and if the contactor is making connection.
The fan and compressor have different capacitors. Possible but not
likely that they are both bad at the same time.
My HVAC took a time-out a few weeks back. Nothing would work at all.
The fan would not even run, like yours.
I presume the fan blower gets its 110V power from a light switch box
in the attic. The switch had failed and no power was getting to the
If the inside unit is not working then it's likely that the 24 vac
transformer is not getting power and that will explain why the outside
unit doesn;t work. The op was not very clear about the inside half
but I got the impression it was ok. I could easily be mistaken.
On most of these the 24vac power comes out from the air handler to the
outside unit. It's how the insde unit turns on the outside one. So
yes, sounds like you should troubleshoot the 24vac. Start at the
outside relay and work back to the air handler checking for 24vac when
the inside unit is running in the cooling mode. The 24vac wire
should be color coded so you can find it at the inside unit if you
have to go back that far. Obviously if you have 24vac at the outside
relay then you have a bad relay.
The air handler does work, and when I push in the relay on the outside
compressor unit it runs, so I guess next I check for 24v to the
The only thing controlling the 24 volt system before it gets to the outside
unit is thermostat. Are you sure it is good? Find the two wire cable and
test for 24V there first.
Many of the 1995 and later models have a low pressure switch wired into the
24 volt system inside the condenser unit. This part might also be the
problem. Just mentioning these two things BEFORE you run out and buy a
Follow the 24V wires and test for current after each part. Entry point, low
pressure switch and at the contactor. Actually working that in reverse is
the smarter way to do it. I just wanted you to see the path.
Please come visit http://www.househomerepair.com
He did mention that it's a 13 SEER unit and it may very well have a low
pressure cutout switch. The builder grade units, even the newest of them
don't have a factory installed low or high pressure cutout.
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