If the kit is fitted and no one tells you to leave it off then it should be ON else how do you know if it will work?
You might not need it today but some poor sod who gets your plane tomorrow might get heartedly pissed off if he was the one to discover it was knackered.
We had this ince with a bombsight. Had a week's ranger intended for calibration totally f*cked up as the previous crew found it didn't work, switched it off, and did not report it u/s.