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Came home to a hot house! Condensor fan not coming on...

8K views 12 replies 6 participants last post by  MgMopar 
#1 ·
I came home to a hot house today!

The thermostat had been set to 76 when I left for work this morning, and came home around 5pm, and the house was 80 degrees, with the attic unit on, and air blowing out the vents. I noticed that the outside condensor fan was not turning on.

I replaced the condensor fan motor and capacitor about two weeks ago as the bearings had went out on it, and things have worked fine until this afternoon, so I can't imagine that the motor already went out on me, but don't know what else to look for. Where do I began to troubleshoot? Any and all help/advice greatly appreciated. It's already getting hot down here in Austin


Sytem Details: Split type Unit with American Standard Allegiance 14 on the side of my house and an American Standard Freedom 80/TXC03653HPA1 (the 5 could be an S; not sure) up in the attic.

When I was up in the attic, I noticed that there was something dangling on a wire, coming out of the Freedom 80. It didn't look right, so I took a picture of it and inserted it below. It looks like some sort of a switch or fuse. Don't know what relevance if any it holds for my problem.

http://www.mediamax.com/austinringdi...d/CIMG2078.JPG
http://www.mediamax.com/austinringdi...d/CIMG2077.JPG
http://www.mediamax.com/austinringding/Hosted/CIMG2078.JPG
 
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#2 · (Edited)
1. When the thermostat calls for cooling and the air handler comes on what happens at the condenser? Does the compressor come on? Does the compresser and outdoor fan unit both come on? Do they both come on at the same time and then shut off? Does one component shut off sooner then the other?

2. If they don't come on or if they shut off prematurely is the contactor signal energized? Usually Yellow wire.

3. Do you have 24VAC power at the condenser's control board?

My guess is you disturbed the condenser's control wiring while you were replacing the fan motor. (especially if the compressor no longer runs)

I really think you should call in a pro unless you have some basic electronic troubleshooting skills.

P.S. I wouldn't get distracted with the air handler. If you didn't touch it and it worked fine before your ODF repair and works fine after the ODF repair then it shouldn't all of a sudden be a source of your problems. I don't believe in simultaneous coincidences when it comes to troubleshooting.
 
#3 ·
hi, and thanks for your response.
I do have some experience with electronic troubleshooting and have done a lot of remodelling, which has included a lot of electric service work. I know how to use a multi meter, etc, so I'm not scared of at least doing a little more troubleshooing, and learning a bit along the way.

I do not believe that the condensor is getting power to it, as I haven't heard it go on when the thermostat turns on, but I will check more diligently after work today. The condensor fan never turns on no matter how long I leave the Air Handler unit running.

As for the contactor signal, where is the wire located for it? Inside of the condensor housing by the capacitor, etc? Is it possible that I may have hooked up the wiring wrong when I replaced the fan motor? If so, how would it have been working fine for two-three weeks?

As for the control board, is that some sort of type of green circuit board? If so, I haven't located it yet. Is it right on the condensor itself, or just somewhere inside of the fan cage? The condensor itself is at the bottom of the fan cage with an orange poly/foam sleeve over it to protect it from the elements. Do I need to remove that to get in there?

looking forward to your response...:)
 
#10 ·
ok, i got the float switch re-attached properly to the side of the drain pan, and tried it again. nothing. so I went out to check the breaker and it was broken; I turned it back to ON, and within seconds it "broke" again. I'm going to open the fan cage back up and look at the wiring connections that I did when I replaced the motor; see if anything is awry there. Any other suggestions?
 
#11 ·
ok, i got the float switch re-attached properly to the side of the drain pan, and tried it again. nothing. so I went out to check the breaker and it was broken; I turned it back to ON, and within seconds it "broke" again. I'm going to open the fan cage back up and look at the wiring connections that I did when I replaced the motor; see if anything is awry there. Any other suggestions?
How do you know the breaker isn't shot? Have you tried to replace it?

I had a similar problem after installing a new air handler. The breaker would keep popping off. I looked high and low for wiring problems but found none. It turned out the breaker went bad.

My theory is that I was turning the breaker off and on during the install which pushed it over the edge. It was about 25 years old so maybe the internal spring was weak which kept it in the on position.

Just a suggestion.
 
#13 ·
Go ahead and double check your work. You could even try the unit for a moment (like 30 second or so) without your condenser fan wired in (just to make sure it's not from what you did). Be careful to cap all live wires when doing so! This would tell if the compressor is shorted. If it runs too long the head pressure will rise and overheat and overwork your compressor. But fine for a test.
When your unit ran for the time without the fan before your replacement of the motor it could of easily overheated a aged compressor to bring it to a end. If you have ability to check current loads with a clamp on ac amp meter you could check to make sure your breaker is functioning. At that point the same meter could be used to find out were your large draw is. Could possibly be your compressor it self. It you are not that familiar with it then I would agree with havactech that it time to call for a contractor.
 
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