I fired up my air condition for the first time this season (single family house) and felt lukewarm air coming out of my ducts. When i went outside i saw that the condenser was not turning on so I went to the furnace and saw that there were two wires just dangling there inside of it, red and white colored (my furnace was replaced at the start of this past winter so i think the installer was negligent). After some googling, i learned that i needed to insert the red wire in to Y and the white wire in to C, so i did and now it turns on.

Now when i turn my A/C on i feel cold air and everything will run fine for about 10-15 mins, sometimes less, but then the blower turns on and off repeatedly. I also hear loud clicking noises associated with it turning off and on.

Any ideas?

here is a picture of my wiring, the red and white wires coming out of the brown sleeving is what i hooked up to Y and C: enter image description here

and in this picture, the T in the red box is my current set up to drain the water out. I still have to get PVC and run it to the sump pump, but thought id show it in case anybody thinks it could be the reason. enter image description here

https://www.dropbox.com/s/tfvjsvricftc3gs/IMG_1627.mov?dl=0 ^^ link to a video of what im experiencing. may have to get close to your speaker or use headphones


  • Do you have a multimeter or non-contact voltage tester? – ThreePhaseEel Jul 1 '19 at 2:54
  • yesssssssssssss – homediyer Jul 1 '19 at 22:14
  • Can you use it to read voltage at the fan terminals/leads while this is happening? – ThreePhaseEel Jul 1 '19 at 22:41
  • this one is solved. turns out with new smart thermostats (i have a nest) you need to have continuous power flowing to it via the C wire (blue). i didn't think about this because over the winter the heater worked fine as well as just running the fan. i guess when you run air conditioning it uses more power, which is why the nest needs to have dedicated power – homediyer Jul 3 '19 at 10:44
  • Post that as an answer and I'll give it a +1 :) – ThreePhaseEel Jul 3 '19 at 11:30

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