Since I'm also considering a solar panel for my 22' CCD, I'm very interested in the outcome of XRAY's situation.
I was reading my Airstream manual after talking to X Sunday night and discovered that the Disconnect Switch will isolate the battery from being charged by the AC converter/ charger while in the "Store" mode. The converter will still provide DC directly to the DC appliances and "cigarette lighter plugs", while AC is applied to the trailer. No mention was made to "Phantom" loads. No mention was made to the solar by-passing the Disconnect Switch, however, it did mention that if the 7-pin connector umbilical is connected to a running tow vehicle, the alternator will charge the house battery, regardless of the position of the Disconnect Switch.
I think I'm going to get my trusty multi-meter out and start troubleshooting.
In X's case, disconnecting the battery and checking voltage at the + and -leads, while the Disconnect Switch is open, will indicate that the solar generated DC voltage is indeed getting thru to the battery as it supposed to. Also insure that the 10 Amp in-line fuse is good. Then flipping the Disconnect Switch to "Store", check to see if voltage is still present at the battery leads. I'll be interested in the results.
The battery is probably dead.
If XRAY's battery was completely discharged by "Phantom" loads, it's electrolyte can freeze at +19F, according to the manual. Not being a battery expert, I don't know if the battery can be brought back into service, if it froze.
This is going to be an interseting thread, and I hope that the A/S tech people on this forum will contribute as well.