5S-FE MK2 Non-Turbo Engine Stereo draining battery?

5S-FE MK2 Non-Turbo Engine, stereo, battery, dead, figure, completely, monday, prevent, happening, late, work, coming, drain, hours, installed, draining, similar, problem, driving, time, atleast, drive, weekends, works, longer, install, shop, fixed, afaik

I had a similar problem when I first got the stereo installed, except it would drain the battery within 8 hours of not driving. The shop I got to install it fixed it afaik. Now, my stereo no longer works (90% of the time, atleast.) I usually don