My problem is the fuse that allows you to run a obd tester keeps blowing out...I went to get an inspection sticker and the test would not work because no signal was coming out of the port...so back to the shop I go...find a blown fuse..replace it and it works fine for about 2 mins..than the fuse snaps....now, I replace the fuse....and just sit there with the key on..no obd tester hooked up...just the new fuse and sure enough..two mins go by and SNAP!!...Any clues to this problem?