The RV is a 2009 Dutch Star. The ducts are all connected and run almost the entire length of the coach in the ceiling. The ACs are sealed in the roof. Nothing in the troubleshooting manual about this symptom. The fan and compressor run just fine. Also, when another AC is turned on in addition to the culprit unit, the airflow from this AC comes out as normal.
If the ducts are blocked the airflow from the culprit unit would not be become normal when an additional AC is turned on. I will try to get a mirror and a flashlight and investigate the ducts.
I will call Dometic but in the past their customer service has been limited in terms of troubleshooting help.
We have 3 Penguin dometic AC/heat pumps in our RV. Each unit is allocated a zone. So, I can turn on each unit independently at the control unit. When I turn on unit 2,, I hear it come on and I hear the compressor engage but I get no air flow out of the vents for unit 2.. However, I get a small air flow through the vents allocated to unit 3.
Now, when I turn on unit 1 and 3, I get a air flow through the vents of unit 2 (which is normal). Now, when I turn on unit 2 when 1 & 3 are on, I get lots of additional airflow through the vents of unit 2.
It seems that unit 2 pushes air through its vents only when unit 1 and 3 are on. This was not the case before. Kinda strange.
Any ideas or comments on how to remedy this issue would be much appreciated.