I have looked and searched, but still iffy where to connect the c wire coming from the thermostat.

a/c wiring

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I appreciate any help.

  • It's really difficult to tell what's going on in the photos. It just looks like a rat's neat of wires. – Tester101 Mar 16 '15 at 2:16

"C" is not always labelled as such.

If you can determine the two wires on the 24V side of the transformer (load side), then find which of the two wires on that side is running to "R" on the thermostat. The wire NOT running to "R" is always "C".

  • Good method. Grab the meter and test away. I had to do this when replacing my thermostat that someone had wired all in the same color of THHN. What a jerk... – BrownRedHawk Mar 17 '15 at 19:59
  • In my case C was exactly this -- and it was also connected to the ground/frame of the furnace. It seems that C could be better explained as such -- the non-"R" side of the thermostat or, even better, ground, if this is the case. When I read most explanations, that it was necessary to have constant power at the thermostat, it confused me more than anything. – sshanky Jan 5 '16 at 17:10

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