Wifi thermostat won't start AC, everything else works

I'm attempting to install a Honeywell RTH6500WF thermostat. All the wiring appears to be correct, but something must be wrong because it won't start the AC unit outside. The thermostat itself appears to be working fine. It shows "Cool On" and turns on the blower fans just fine. Pictures of the wiring from the furnace unit and the old thermostat are here. I've tried having everything wired letter-to-letter on the new thermostat, and it just gets me the situation described above. Last I measured, I was getting 28.5 volts between R and G, so I think that is good. This is my first time doing anything with a thermostat. The old wiring was:

• G -> G
• C -> Y
• W -> W
• R -> Rc, jumpered to Rh

I'm not sure why/how C was wired to Y. We just bought this house. I did find a receipt showing this thermostat was installed by a service company back in March of this year. It is an Emerson programmable thermostat.

Any ideas? I really appreciate any help! Thank you!

submitted by /u/moffman3005
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