Central air fan not running

[AceHighFlush]

Hi everyone.  I've been surfing all over the net trying to find a place that can help me find out whats wrong with my AC.  Hopefully, this is the place.  Here is my problem.

I came home and the central air unit outside was buzzing but that was it.  No fan, nothing.  I shut it off and waited about an hour to start it up.  This time it sounded like the compressor was trying to run, but the fan wouldn't.  I gave the fan a nudge to see if it was binding, but it ran freely and actually started to run.

Although the fan didnt seem to run at 100%(maybe 75% normal speed) cold air was again flowing through my house........for about 10 minutes.

The fan on the central unit stopped and would not go even if I prodded it a little.  The compressor was still making a noise like it was trying to work, and parts of the unit were extremely hot.

I have read similar posts, but I would more than appreciate any insight as to what is actually going wrong and what I would have to replace.  I am a jack of all trades, and master of none and dont mind jumping into a project I know nothing about as long as I have some good advice leading me along the right path. 

And brothers and sisters, I'm at the bottom end of the learning curve when it comes to central air. Thanks.

[AccApp]

You solved your own problem right before your own eyes. Replace the condenser fan motor. Any mfg's markings on the unit? Model? Serial number?

The compressor has an internal limit which protects it if it gets too hot. When the fan stalls the compressor overheats and stops. Applianceman had a post a while back about getting the fan blade off the motor. It's not a hard job if you can get the right motor.

[applianceman18007260692]

before you replace the fan motor check the capacitor to see if its leaking or swollen  and let us know dude

 

[AceHighFlush]

Hi guys.  I checked both capacitors and they look fine. So I went and bought another fan motor and a new capacitor for it(was only $6)  Here is my dilemna....there is an extra wire on the new motor.

On the old motor there were 3 wires, yellow, black and brown.  On the new motor, I have yellow, black, brown and brown/white.  I was told to hook up the brown and brown/white to the new capacitor and then just connect the Y and Bl to the old connections.....but.....

When I looked at the old connections it went like this.  Yellow was connected to the main power switch while the brown and black were connected to the capacitor.  On the black connection side of the capacitor there is a black jumper cable leading to the power switch opposite the yellow.  Soooo, if I hook up the new motor and connect Br and Br/wh to the new capacitor, Y to the Y, I still have the black that I'm really not sure where it should go.

Should this also be connected to the capacitor? along with the original black jumper?  If you can decipher this mess, I would be grateful. 

Sitting here sweating my Ace off.......

[AccApp]

If the yellow lead is hooked up to unswitched L1, hook the black wire up to switched L2. Just make sure you get the rotation direction correct, most replacement motors are reversible. Also make sure you secure the new cap so it does not bounce around. Take out the old cap and remove the black jumper wire, hook up the new motor's black wire where the jumper was connected.

[Guest ahammer48]

Hello

U don't have extra wires:) Ur new mtr is just wired differently then the old one. The yellow and black are the power wires and the brown-brn/white go to ur capacitor.

Turn Power off !!!!:poison:

With UR old mtr the black wire went to a power source (L1). Connect the black wire of the new mtr to this connection. Now on the old mtr yellow and brown went to the capacitor. Yellow(most likely) went to the terminal of the cap with another power wire on it (L2), and brown was on the other capacitor terminal all by itself.

What U have to do now is hook the yellow of the new mtr to the wire that was on UR old capacitor with the old mtr yellow wire(L2). Just splice them together. They do not go on the capacitor any more. U should now have UR blk wire connected to a power wire, and the yellow should be connected to its own power wire. . The brown wire goes to one terminal of UR new cap and the brn/white goes to the other terminal of UR new cap

Hope this helps:)

[AceHighFlush]

hey Ahammer. I'm glad ur on. Dont leave , cuz this is not working

 

[AceHighFlush]

On the old mtr, the black and brown went to the cap, while the Yellow looked to be hooked up directly to the "main switch".  I was told to hook up the brown and brown/white to the new cap, and on one side of the cap, attach both the black wire and the black jumper wire that was hooked up to the old cap.  Well, i did that and nothing.  The unit just buzzes and no fan movement.  Before, I could at least give the old fan a push and it would work for 10 min.  Now, nothing...Let me know what you know please.....

[Guest ahammer48]

 Im here stand bye 4 help ok

[Guest ahammer48]

Ok. With UR new mtr only brn and brn/white go to the capacitor. thats it, nothing else. Brn to one terminal and brn/wht to the other

Thats leaves black and yellow(the power wires)

turn power off:poison:

I think in UR post U said yellow went to a switch? Most likly U meant the contactor:) Connect the yellow lead of ur new mtr to this same connection(L1). That just leaves the black wire.

On the old mtr U said the black wire went to the cap and there was a jumper wire on the cap with it. That jumper wire is (L2). Another power wire. Splice the blk of the new mtr to this jumper wire.  Your fan mtr should now turn when U re-apply power and make a call 4 cooling.

Do U have a volt meter???  U can make this check before hooking any thing up, but it has to be done with power on so BBBB very carefull.

If U touch 1 test lead up to where yellow was connected to and touch the other test lead up to the black jumper you should read 208-230VAC. If U do then hook the mtr up as I perscribed

Get back to me  

[AceHighFlush]

Hi Ahammer.  Thanks, I am off to hook everything up as you described... Give me 5-10 min and I will let you know....thanks.

[Guest ahammer48]

I'll B here good luck:)

[AceHighFlush]

hi ahammer. Ok, i hooked it up as you said and still nothing.. when set to cool, the unit buzzes and the switch depresses on the unit, but nothing else......I tested for power at the lead points and it came up 0.....if this is a fuse problem i'm gonna kick the dog.........real hard.......Let me know ...thanks

 

[Guest ahammer48]

Hello

Yeah thats what it sounds like. U  have 2 main power wires coming into the unit from the disconnect switch or circuit breaker. With power on to the unit but the thermostat off check the voltage on these 2 wires.

 Again it should be 208-230VAC. If its not then the prob is ouside the unit, most likey a blown fuse. If it is then we need to dig deeper. Let me know

 

PS. If U'd like U can send me a private message by clicking on my handle, instead of having to post all the time.

[AceHighFlush]

Hi Ahammer....Ok, i just kicked the dog....not getting a reading...i'm running down to the hardware store to get replacement fuses.....let you know in 15.....thx

 

[Guest ahammer48]

Give the dog a bone. Its not his fault:) B careful changing out the fuses

[AceHighFlush]

Lol, didnt kick the dog, but gave myself a good kick in the Ace.....After changing the fuses, she's up again and purring like a kitten......My pregnant wife and 3 year old daughter send their thank-you's.......And I send a thousand thank yous for staying on line with me while I muddled through this:D....You are truly a scholar and a gentleman Ahammer and the cyber repair world is a better place with you in it.  Thank-you. 

Question though, first thing i did was check the fuses and they were fine.......did I do something while changing the fan motor to blow the fuses?

Signed,

Cooling off with an ice cold beer in my soon to be cooled off home....

[Guest ahammer48]

Hello

 Thanks 4 the kind words.  U and the family are most welcome. I think I need 2 open up my own school. I love teaching this stuff. HVACR is the best field (IMHO:)).

I get 2 work with my hands & my head, and its been very, very, good 2 me.

Its possible that 1 of the mtr hook ups could have taken out the fuse. The best way to check a fuse is with continuity ( no power and the fuse in your hand:)) 

Enjoy the rest of the summer !!

[applianceman18007260692]

well done hammer! keep up the good work!