Find the converter and check the fuses. I had a fuse that was improperly installed and it was causing me the same problem.
Beautiful wife of 28 years
21 year old son, college student
100 lb lap dog (Black Labrador & Rhodesian Ridgeback)
2002 F250 4 door, 8 foot bed, 7.3 PSD with Hypertech software, timbrens, 3.73 rear axle
2006 Montana Mountaineer 344RET
Be sure the battery is connected properly. There is usually a diagram on the rig at the battery area. The correct hookup actually includes reversing the cables as the diagram shows. If this is correct go to your fuses at the breaker box. You will probably find one for the inverter is blown. I had to disconnect the batteries, change the fuse and reconnect the batteries. This was because Sears hooked up my battery cables wrong and blew the fuse.
Good luck.
Lei & Howard Hale Huaka'i
"The Traveling House"
2004 Keystone Cougar 29RLS
2004 Dodge Ram 2500 Hemi 5.7
1999 Honda Shadow 750
Mine is an '08 and it has a fuseable link about 2' from the battery back along the frame.It's a brass strap that will melt through if it shorts out,don't know if yours has one there or not.
2008 Keystone Cougar XLite 29RLS
2006 Super Duty V10 6 Speed 4.10S Tow Command Tow Pkg. 4X4