Engine light on Horn not working any ideas?

[mikesz]

Hi all, a week ago purchased a 99 Boxster . Coming home the check engine light went on. I live in RI and the next day it was like the antarctic and the battery died so I replaced the battery. I think I left the interior light on. So by changing the battery I reset the check engine light. So I have been driving it and check engine light went on again and the horn doesn't work. I checked the fuses for horn and there was a 30amp fuse where a 25amp should be so I replaced it. Horn still doesn't work when I press the steering wheel. I know in order to take apart the steering wheel with airbag I will have to disconnect the negative battery cable but I am concerned about resetting the check engine light again. I am currently driving on temp plates so I have to register the car and get it inspected. I am afraid that if I take it to be inspected and they detect the engine light has been reset too many times they will fail it then I will have more of a problem.

How should I proceed?