alrite i got my scan gauge today and i tryed use my horn and see if voltage would change but it didnt. my normal voltage when engine is running is between 13.5 and 14 with all my lights on and everything and it chnage only 1-2 points when i use horn. Also i noticed it dim a lit bit at day time too wjen all ligths off. So now im confused what it could be? Any suggestions?