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Old 09-16-2016, 10:32 AM  
o2284200
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Default Thermostat clicks but nothing happens

Hello all!

A/C has been running fine until last night. The thermostat clicks but nothing happens; neither the outside fan nor inside fan turn on. Fans will also not turn on, if switched to "On", instead of "Auto". I checked breaker, still on...I turned it off, waited 30 seconds, turned it back on, which did not help. FWIW, I also put fresh batteries in and cleaned connections about one month ago.

Your thoughts are greatly appreciated, thanks!


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Old 09-16-2016, 10:47 AM  
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I would say a starter cap, but I believe the furnace/air handler fan would run regardless of a cap failure. I just had one of these failures this year.

Another question is the "light switch" to control power to the furnace/air handler. My three year old grandson turned that off once unknown to my son. Typically around here they are mounted on the furnace/air handler.

Just guesses......good luck.


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Old 09-16-2016, 11:09 AM  
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What is a "starter cap"? How does one troubleshoot it?

The only "light switch", other than the breaker is behind the unit and not accessible. I checked the breaker, it was still on...I turned it off, waited 30 seconds, turned it back on, which did not help.
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Old 09-16-2016, 11:20 AM  
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The cap is located on the outside unit. Troubleshooting is problematic unless you have the correct meter however the caps are fairly inexpensive (20-40 bucks) and not too difficult to change. That said, if you don't know your way around electricity either find a competent friend or hire a pro.

Google AC starter cap and I bet a video pops up.....

Again, I have some doubt that is your issue since the inside fan is not working.

I'd start at the thermostat.......

Someone with more knowledge than I will jump in here soon.....

edit----I see you are in south Florida and may not have the combo of furnace/AC that I am used to seeing.....so my answers are subject to being totally off base.
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Old 09-16-2016, 07:57 PM  
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Problem is not the cap, symptoms don't lead to that.
You have to trouble shoot your way through but I'm putting my money on a blown control board fuse.
Check that first. If it is good then post pics and find your volt meter.
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Old 09-17-2016, 08:10 AM  
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Thanks!
How do I check for a blown control board fuse?
Here are some pics:

Air handler wiring




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Old 09-17-2016, 03:01 PM  
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I found one large purple fuse, inside air handler, which looks OK
FWIW... I have one of those cheap 7 function digital multimeter from HF as well as a Milwaukee pen style digital multimeter.

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Old 09-17-2016, 03:17 PM  
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First ,check and see if its a bad thermostat,by bypassing it.
Take the thermostat cover off, then take the red,and yellow wire and connect the two. no need to turn the power off,its only 24volts and will not harm you.. did the system start ? if yes, then replace your Tstat. If not,then connect the wires back as they were,then procede with the following.

3 things you can do yourself , and for your situation, I would turn off your power to the outside unit. Open the panel and look at the capacitor. Is it swollen on top ? if yes,its a bad cap. ,if not swollen, I would take a multimeter and check voltage to the contactor, on the terminals L1 and L2 ( that's the power coming from the outside units power panel) from the house . Check L1 L2 and make sure you have 240 V. ,next you could take an insulated screwdriver and wear heavy rubber gloves,and press down on the contacts for a second and see if it all starts up.. If it does then its a bad coil not pulling the contacts down on its own.. Be carefull around the electrical part,get someone to do this if your not comfortable.. A capacitor and a contactor both cost about $25-35.. you'll save a ton if you can do this

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Old 09-17-2016, 03:41 PM  
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Here is my capacitor I just changed last week. The new one is on the left, and bad one on the right.. You see how the top is swollen ? That's a sure sign you can look for... If you find it bad. Note,your wiring.. Brown = Fan .. Yellow = C (common) and Blue = Herm (that's the compressor) ..
Power off on the outside unit, drain the capacitor by touching a screwdriver across the terminals on the cap . They can hold enough power to shock you even when disconnected,so play it safe and drain the cap before handling..
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Old 09-18-2016, 02:28 PM  
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Fuse is good.
Start with line power to the unit.
Check the control board for flashing light code & reference code the legend on back of cover panel.
Check for 24volts on the secondary side of the transformer.
Check for 24vokts at the tstat.
Post back findings.


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