My Subaru Outback is currently stranded, unable to start or turn over. I was able to correct this issue roughly a month ago after removing then reconnecting the battery terminals. The battery has been tested and passed with no problems. I also noticed that the car has power when the key is in the on position but loses power if I apply the brakes or turn the ignition to the "start" position. I also saw a bit of corrosion on the negative battery terminal so my next step will be to grab a multimeter and go check voltage to the terminals. I'm sure both incidents occurred just after a heavy rain storm but that could be a coincidence. What else should I check when I get my hands on a multimeter?