First off, welcome to the forum.
Unfortunately you have not heard that Sunline is out of business. They shut their doors November of 2006 in the hopes of selling the business, but that plan did not pan out. They have since auctioned off all physical assets. The proprietary information was also being auctioned off, but I have not heard any information on that wrt a purchaser.
Here’s a link to a Sunline Closing
post and here’s a link to the Sunline Auction
post, if you’re interested on more information on the unfortunate demise of Sunline.
With the closing of Sunline, many of us here look at the Sunline Owners Club as one of our major sources of information to aid in maintaining our Sunlines.
Members here have extensive experience and knowledge of Sunlines and are very will to help. Hopefully someone here will be able to provide you with information that will help solve your problem.
Some additional information may help in troubleshooting your problem.
During your 12 day trip:
> Were you at the same place the whole time or traveling from place to place?
> How often were you connected to shore power (or were you boon docking)?
> How much time was spent connected to shore power, connected to tow vehicle, and boon docking during the 12 day trip?
> If you were boon docking, do you have the refrigerator’s Climate Control Switch turned off?
> If you were connected to shore power did all other electrical appliances (e.g., A/C, Microwave, etc.), electrical plugs, etc. work ok?
> Do you have both batteries hooked up (or did your replace the 1st battery with the 2nd battery)?
> If you have both batteries connected how do you have the wired (i.e., series or parallel)?