Motel style heat and air

HI,
Meaning not function of heating,pls apply this the following 1) Possible loose connection to reversing valve pls check this wiring connection.
2) Pls check the sensor to thermostat if this a loose connection.
3) Check the Compressor if this not function or loose compression.( Function but not heating )
4) Check if have a Leakage.

Pls go to the nearest repair shop if not solve,

Thanks & best regards,

Edgz