I'm looking for some help with a really weird issue, and I'm totally out of my depth. My heat pump is only blowing cold air from the compressor, no matter which way the reversing valve is set (O or B). It seems to be working otherwise, the compressor runs, the AUX heat works (thank goodness).

I'm assuming this is a wiring issue, but I've already checked the thermostat wiring and it seems good, but once we get to the compressor and the air handler, I don't know what I'm looking at. I couldn't even find a control board on the air handler. The wires seem to go all over, and where the connectors are, there are even different colored wires at some of the plug splits.

It's a newly built system in a newly constructed house, and I have a feeling the installers didn't know what they were doing since it was new equipment for them (they admitted such) and presumably used in lieu of their usually installed equipment because of COVID-19 related shortages. When I moved in it was all disconnected and the only heat was on W1 (AUX only) when I got it all powered on. That's since been fixed, but I can't figure out why it's not heating, even after toggling the reverser for O/B. I've confirmed the compressor is turning on and the fan is spinning.

Thermostat is properly programmed for heat pump as well. I've even replaced the thermostat just in case, but the new one did the same thing so I put the T6 back on.

Equipment:

• Honeywell T6 Pro Thermostat (Wiring Image)
• Champion TH16B2421SB (SEER 16 Modulating)
• York AE24BX21G Air Handler

I have images from the air handler's interior as well, but I can't make heads or tails of what I'm looking at. Those can be found here: https://lensdump.com/a/rtMyF

Any idea what could be causing this?