Added cigarette lighter and alternator charger. I don't think it can be either of those. Main power switch on dash now stays brightly lit when it use to dim. Problem is nothing is running. No lights on LSS box. Could something at motor be energized with key off? I am going to start with disconnecting accessories at battery. I have all wires on one terminal so no biggie.

My buddy had the same problem (Ranger) and we think its a worn out cut off switch that came factory installed. He did away with it and bought cutoff switches that go onto the battery post. Problem solved!!

I was going to swap switches. I have 3 that do nothing. I just can't imagine that the light on switch is draining battery in a week.

check your battery for a bad cell, also load test it.

you can buy a load tester at oriellys, wal mart, etc. for 25-35 $, they are about the best way to test batteries.

hydrometer can be had at the same places for 5 $ or so, test ea. cell with it.

Do you have power poles if so do you have a breaker switch to turn them off if not they will drain battery and some of the old structure scans needed a switch to turn them off also. If I can help let me know.

A couple of more things to check
NMEA devices suck as GPS puck, temp sensors etc... If the power to the NMEA network is not on a switched circuit the connected devices will continue to draw power.
Radio will draw power even when off to maintain the internal memory.

Radio is on other battery and LSS is only powered with main power switch on. I have a hydometer and will check battery. Battery is about a year old. I know from experience that does not really matter. They can go any time. I put a switch on the ground from battery that feeds the power switch. Will see how that works.

I thought I found the problem. My LSS box had power when switch was in off position. I pulled all power from switch panel. Battery still dead in a week. Starting to suspect key switch. Next step will be to start disconnect the alternator charger then wires to the motor.

Looks like it is back to suspecting the downscan box. Even with trigger (yellow wire) disconnected the power light is lit.