I had the fan motor of my outdoor AC unit replaced about 5 years ago, it has an AO Smith mod F48K92A01 which I found online for about $65 but want to make sure it is not possibly the capacitor or something else first.

I caught the unit having the fan hitting the splicer near the top, clank, clank, clank, so I ran in and shut off the unit. Then I pulled the top and put all the wires back into the protector thing and up out of the way. I had pulled the main fuse for it after shutting it off. However it had a brown and white wire just sitting there too in addition to the ones in the splicer. When I got it back to together doing nothing with the two loose ones, as it was running without them anyway, it would not go. Dead, nothing.

1. Could it be the capacitor? 2. Those two dead end brown and white wires? 3. The fan motor as I think it is, but it does not even moan like last time, nothing. 4. would a rest help? 5. something else?

I watched very closely last time the repair guy came out so I could do it myself, which I can, but want to know if it is something else first, and if I should replace the capacitor too along with the motor unit.

aarkon :confused:

1. Could it be the capacitor? 2. Those two dead end brown and white wires? 3. The fan motor as I think it is, but it does not even moan like last time, nothing

Yes it could be any one of them.

would a rest help

NO they are designed to run all the time if necessary.


should replace the capacitor too along with the motor unit.


YES replace the capacitor with a new one designed for the new motor.

When you say brown wires loose they usually the go to the capacitor to start with unless the last repair person wired it a different way.

So hvac1000 what do you think? I thought it funny too that there was two wires left over -- one white and one brown, just like what is connected by the splicer still there. In the bottom of the unit was a splicer but it could have been from the old replacement. Is it just a splicer or something else? I could just jury rig the wires for now and see what happens, maybe the blades cut it. It was banging but being outside, in California you don't hear it unless outside the living area.

UPDATE: I now have air at least for now. I monkeyed around and finally got a URRRRrrr sound from it, so kick started the fan like a WWI airplane and it started up slowly and is running fine now.

The question is why and what is wrong? Can any one help out. I know very little about compacitors, could it be that, and what do they look like and where do they go. Could the unit have two? The two loose wires are black and white not brown and white. They are still loose cut off flat as before.

Any ideas guys? Right now I cannot afford to pay someone to fix it, but can afford the capacitor or fan motor, but the labor is a killer here, probably everywhere too, but you get the point.

aarkon (please post here as I can't put my email here for answers)

The fan motor could have cooled off and reset the internal overload. I have no other ideas as to what is going on.

Okay thanks. It would not start on its own this morning, had to give it a nudge with a screw driver. If anyone else has any ideas please add them and I will check periodically.

Can the fan run without the brown wire atatched to the capacitor

Can the fan run without the brown wire hooked to the capacitor

Want would be the problem
If the fan ran and started without the brown wire hooked up

Okay thanks. It would not start on its own this morning, had to give it a nudge with a screw driver. If anyone else has any ideas please add them and I will check periodically.

Hey I don't know if you got squared away but your motor should have at least three wires going to components in the electrical cabinet. There may be a couple of more that change rotation of the fan blade but forget about those.

I know I have put in a bunch of AO smith motors and I just looked to see if I had one in my shop to get you a rundown on wire colors. I don't but I know on the side of the motor it has the wire leads and where they should go.

You may have one extra wire and that would be for a '4 wire' hook up.

anyhoo if you are able to nudge your motor to get going than I would look at testing/swapping out the run capacitor. If you are still not getting a start then the motor is going bad or possibly a wire issue and subsequent voltage drop.

Last thing hvac1000 mentioned overheat. Is the outdoor coil clean and air moving freely (minus the knocking the fan blade)?