HVAC guy didn't connect the AC condenser/compressor to the furnace/blower. Found the 24v common/cooling wire running from the condenser unattached. Questions about connecting it.

Our house is a new build as of April and was close to 90 degrees inside today, despite the AC supposedly running all day with it set to 76. Odd, but I thought maybe the Ecobee3 assumed my wife and kids were away and they might not have passed any of the sensors or thermostats in the house (3 sensors and 3 tstats, hard to believe but whatever). I set the Ecobees to hold 70 degrees see what's up. No dice. While doing some work outside I realize the compressor never switched on. I check the furnace/blower and see an unattached red/white wire, and I traced it from the furnace to the AC condenser outside.

I've installed the Ecobee3 and added the c wires no problem. I've also done plenty of electrical work in the past and can read wiring diagrams to an extent. However, this is the first time I've come across a household condenser issue (very familiar with cars, though).

York HVAC setup (condenser, furnace, etc). Luckily the manual was around for me to read the wiring diagram, and the white appears to be connected to the common 24v terminal in the condenser, so that leaves the red as the cooling wire to be connected to Y/Y1 if I read the manual and diagram correctly.

I attached them to the appropriate C (white from AC condenser) and Y (red from same) terminals on the furnace where the tstat connects in hopes that the tstat will close the cooling circuit to switch on the AC condenser. Is this how it should be? I tested the system with heat, cool, fan only, and it appears to be working as it should. Did I wire it correctly? I understand that just cause it turns on doesn't necessarily mean it's the way it should be.

What could go wrong if I connected the wire incorrectly?

I'm dealing with it myself because the HVAC guy can't come soon enough with holiday weekend fast approaching. I mean it's his fault the AC isn't working, and he should be here ASAP, but I have two kids under 3 who are miserable and can't sleep/nap even with the windows open. It's nice and cool now, but I just need confirmation I wired it up correctly.

Wiring diagrams below:

AC condenser portion with 24v ID'd

Connecting to air handler (our 2 zones upstairs)

Connecting to furnace directly for downstairs single zone

submitted by /u/buttgers
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