Just got caught in major rain, no power after I turned car off

For troublshooting the short, you can get an inline fuse holder from a parts store and a 20-30A fuse or so and jumper that in temporarily to see if you still have a short, and to work on things non-running. That is the cheap, fast way to troubleshoot, IMO. BUT, don't leave the fuse and fuseholder in permanently; put in a fusible link when all is done.