dash lights coming on after washing engine bay

Hello, I've recently purchased a 2002 e39 m5 and I had to replace my thermostat. After I finished I decided to spray the front of the motor with a degreaser which I very lightly rinsed off with a hose. Turns out that was a bad idea... Now my dash lights up with a battery, brake, abs and traction control indicators! Plus my navigation unit / radio turns off when I throttle up the motor. WHAT HAVE I DONE?!?! I've let it sit for a couple of days hoping it'll dry out, but now my battery is dead wtf? I get it running again and everything is still on. Other than that it runs great I don't notice anything wrong. Any advice would be appreciated thanks.