Issue with Lance battery switch (on panel)

On my lance the battery disconnect is a push pull switch inside the battery storage compartment itself, you might check to see if one is there and in the off position instead of on.

It's definitely an automatic (switch on panel) one. If I could find a schematic, I could jumper it (or smack it a little)

The link you gave is to a solenoid , probably a continuous duty one . They come normally open or normally closed . the two large lugs are power in and power out , the two small ones - one is ground and one is to drive the solenoid either open or closed , its probably attached to the switch on the panel,. check with a meter the two large lugs to see if you have 12 volt , or battery voltage on one or both sides , if only at one and you have tried the switch both ways , check to see if you have voltage at the small positive lug , if not put 12 volts to it that should drive the solenoid shut ,could be a bad switch, if that dosent work check the ground to the solenoid . If all else fails replace the solenoid . in the mean time you can tie the wires from the large lugs toghether and you should have power to the 12 volt fuse panel

Good luck