Reversing vavle is not switching. rooft top dometic ac w/ heat pump ac is heat pump , heat pump is heat pump, everything is heat pump .any help?

Unfortunately I have no access to any previous information you received from other experts, but I will tell you that without knowing which ceiling assembly/control box, thermostat etc., that you are using, the most I can do is tell you this.
Blue wire is for the compressor circuit.
Black wire is for high fan .
Yellow wire is not used, unless for heat pump circuit reversing valve.
Red wire is for low fan.
White is the common AC connection.
Green/yellow striped is for ground to chassis.

If the Air comeing out is the same as the temp inside the RV make sure the compressor is running and not just the fans. It could be low on freon. If freon is ok then you would need to ck the wiring to the selector switch for a short. It would be obviouse because there will be melted wires. I am leaning toword low on freon since you have already been inside the wiring/control unit.

Fairly easy. The only thing that you must figure out is how many amps the heat strips will draw. Make sure the fuses and the breaker switch can handle them. And be aware your electric bills will shoot up.

Unfortunately, your rear unit is calling for heat. If you put the rear unit on heat pump mode, does it then cool?
The reversing valve is energized in the cool mode of these AC's. So there is no real way to bypass it. I would check the thermostat and the control board in the unit to make sure that the switches are set correctly.

In the service manual section of the dometic/Rooftop RV Air Conditioner section. I have posted service manuals for the Heat Pump and the Comfort Control.

Hope this helps,

Jeff

Rate me please.

Depending upon the model of your air conditioner, this may be normal operation.

My newer Dometic air conditioner will run the compressor in a "reverse" mode without the fan occasionally in order to heat the coils. This is done to defrost the coils. After the frost is gone, the fan switches back on and everything goes back to normal.

The reversing valve coil may be bad or no power to it during cool. Most heatpumps are set to have the coil of the reversing valve energize in the cool mode. The heating mode is the fail safe mode if the rev valve fails to energize. Check this and let me know.

Would suggest it is drawing excessive current, make sure both fans are going, (inside will cycle low/high), or possible faulty reversing valve solenoid, or could be as simple as loose wire connection, how long does it run for and is it on the same 20amp breaker as the rear?if so start by running only the front unit in cooling 15/20min, check fans running, no unusual bearing noises, switch off for 60 sec then back on heat mode, if unit runs without stopping rewire onto separate circuit, if inside fan not working on heat check bi-metal switch in the airway, if running for a while, fans going but not very warm, check reversing valve.
Note, electrical's should be tested by someone who are qualified in the field.