The unit is air conditioning only and is older (unknown age but at least 10 years, possibly 25). Power was restored to the outdoor compressor and fan: the fuse was somehow dislodged and is now back in place:

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  • Is the fuse designed to automatically push-out (dislodge) due to excessive current?

When the thermostat signals for cooling, the indoor evaporator unit's fan blows air as does the outdoor unit's fan spins-up: confirming that power is restored to the outdoor unit.

  • How can I tell if the compressor is engaged?

The capacitor was photographed to record the wiring:

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The capacitor was tested with an analog multimeter per:


The meter did deflect, although it was very little (10% of the range). Said capacitor did not show signs of bulging, however, a new capacitor was purchased from AMZN and installed:

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I think I installed the wiring as per the original photographs. If not, please indicate this in a response.

  • Is there a good procedure (either documented on the web or in an answer) to diagnose the root cause of the problem?

After letting the system run for 15 minutes, the refrigerant lines do not feel cold, nor is cold air pushed out of the evaporator.

Hopefully, the issue is obvious from the data presented.

1 Answer 1


I am assuming when you stated you let it ren for 15 minutes and nothing got cold or hot and the compressor was running. There are several possibilities.

A. You are out of refrigerant because of a leak. That will need to be repaired and the refrigerant added (Charged). This needs to be done by somebody that understands what they are doing and has the tools, just adding gas will not solve the problem. Running that long without gas can ruin the compressor.

B. You already have a bad compressor. You did not state if the outside fan was not operating so I am assuming it was.

"How can I tell if the compressor is engaged?" With the cover off you would hear it run. My suggestion is to get a HVAC repair tech to check the system out.

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