Does it get any easier? I need HVAC help

[adymond]

It's been nice for a few weeks now and of course as soon as it hits 90 again my AC goes out. I think it is just the fan motor since I hear it start to hum, but it doesn't kick on. Anyone know of a good HVAC person in DelCo?

[jb12string]

Could also be a fan motor start capacitor too

[ungawa]

I was thinking the same thing but it sounds like the guy doesn't want to fiddle with it.

With little single phase TEFC motors like this, only a couple things to check before trashing. You say there is a buzz, make sure it's coming from the motor and not a nearby relay (my experience is not residential HVAC). Might even verify there is proper voltage to motor with your multimeter.

Disconnect all power in a safe and reliable manner. Check that the shaft turns freely (otherwise it is a blower issue and not a motor issue). Take the back off the motor and disconnect all leads from the capacitor (do not shock yourself, it is charged even though power is cut). Look at cap - if there is any leakage or burn marks then it is bad. Sometimes cap is not inside back of motor but mounted somewhere nearby (seems unlikely for these tiny little crappy TEFCs).

Short the cap by bridging the conductors with your screwdriver (do not shock youself) and rub the screwdriver back and forth a few seconds to make sure you have good connection. Set multimeter to DC and check cap for voltage. Anything over a volt you should short again and repeat.

Set multimeter for conductivity (ohms). Check cap, should be infinity ohms (no conductivity, no bell sound from meter either). Otherwise cap is bad. Now, leave multimeter connected to cap for 30 seconds while checking conductivity. You are charging cap with your multimeter. Disconnect multimeter from cap. Switch multimeter from conductivity to DC. Check cap, you should get a spike and it should go down to low voltage very quickly at first and then slower, but almost nothing at 30 seconds. Otherwise replace cap.

If cap works throwout motor. Don't even bother checking the motor windings.