It is entirely possible that it is the motor. If the bearings have lost lubrication the motor may be bound up enough that it won’t run, even though it spins by hand. They are not serviceable and must be changed.
But if it spins very easliy, that’s a good sign, and while it still may be a bad motor I’d still be guessing from the internet that it’s the cap.
A final thought before you do anything rash…
There are other possibilities. If there is a circuit board, sometimes there is a voltage drop—enough that the motor has insufficient voltage to start.
If the cap doesn’t fix the problem-----and if you don’t have a volt meter to confirm a few things-------you may be getting a little in over your head. Maybe.
Changing the motor without a volt meter is a guess. It may be a good guess, but still just a guess.
Changing the cap is a guess too for you, considering you don’t do this for a living and you’re getting advice from the internet.
But it’s a safe bet because it’s easy and inexpensive.
It that doesn’t work, it get more complicated and expensive from here.
I’ve actually had the internal contact on a blower motor burn off but that was on a 110 volt single speed model. I Tim Taylor’d it with a bigger motor.
Good point. I’ve seen that alot on compressors, but on motors from time to time as well.
Appreciate all the responses so far. I have a decent knowledge of electrical systems (if not the inner workings of motors), so I will test the voltage at the relay. There is no circuitry at all inside the air handler, only a relay, a transformer for the thermostat/relay, and a terminal strip for the various wires going in and out.
let us know how it turns out
Thanks everyone for all the help. It was indeed the capacitor (which I should have looked at more closely - the top was clearly bulging). Turned what could have been an expensive repair into a $10 part replacement (plus several hours of my time, unfortunately)…