Originally Posted by jd37055
Where should I even start to look for the problem.
I'd start with the owner's manual. Go to the fuse chart and find out which circuits are covered by that fuse. After that, you need to check each one of these circuits for a short. Unplug them one at a time, then install a new fuse, turn the key and see if it still blows. (Alternately, you can unplug them all at once, turn the key to verify the fuse doesn't blow, then reconnect them one circuit at a time until the fuse blows.) Once you have narrowed it down to one specific circuit which is blowing the fuse, you'll need to inspect that circuit to find out where the short is.
This isn't terribly difficult, but it may take some time to properly diagnose. Hang in there and be patient.