Hi all, working on installing an Ecobee. There was no blue / C-wire connection on the old thermostat, however had the blue/orange/black/brown wires available on the thermostat wire. At the air handler, I confirmed that the blue coming out of it was connected to the C-wire connection inside. I hooked up the blue wire from the thermostat wire to the blue connection (sharing the red connection to the condenser) and checked the voltage between Red and Blue at the thermostat, I got 0 volts (Red to all other colors is 24-27v). I then tried the same with the orange and brown wires. When I check the voltage of Red and Blue at the air handler, I get 24-27v. I'm obviously no expert, but I can't figure out how I would get nothing at the thermostat. Find it hard to believe 3 separate unused wires are bad.

In the pictures below, the brown wire on the left goes to the condenser and the one on the right goes to the thermostat.

A quick summary:

White from the condenser goes to yellow on the thermostat

Red from the condenser goes to blue on the air handler and blue to the thermostat

Red on the air handler goes to red on the thermostat

Green on the air handler goes to green on the thermostat

Brown/White from the air handler goes to white on the thermostat

Any thoughts or help would be greatly appreciated.

Also, the red from the condenser looks like it's attached to white below, but I can confirm it's blue and the blue connection goes to C in the air handler / furnace. It's single stage, all electric.