I installed a new CD player last night and when I started the car it idled very roughly so i turned the car off and restarted it then it idled normally so i went for a drive to buy dinner and no issues. today the car wont start. It just keeps winding over with not even the slightest intent to start. any ideas? i Just checked the voltage with my multi meter and its down to 11.50 (probably from trying to start it over and over again.