What did I do?
Just got my first BMW a 89 - 325i and really think i'm going to like it after I get it sorted out. Anyway today I was doing some maintenance and planned to install a stereo as the old after-market cassette in the dash wasn't even connected (just there to fill the hole in the dash I guess). Anyway I pulled it out, then gently pulled out the stereo wiring to see what was what and quickly abandoned the idea of stereo swap today as I was short on time and the wiring color codes were different that what I've worked on. I then topped of the coolant and overfilled the plastic container causing a little antifreeze to spill. Since there are animals around I wanted to be sure none of them drank it and rinsed the drivers side (US) of the engine compartment. After starting the car I noticed that the tach and MPG gauges were dead. I checked the fuse box and saw that fuse #21 was blown and I replaced it. The tach now works fine but the mpg gauge is stuck at the maximum mpg.
I know better than to do anything electrical without disconnecting the battery but messed up and hadn't disconnected it until after I blew the fuse.
Question if it's more likely that I did something under the dash or if the water under the hood caused a short there.