While driving home the radio and blower died; after this happened the car engine started running rough when stopped and in park. why?
My car normally dims the lights when at a stop to conserve energy, but never turned off any components. I checked the fuses and they were good. I'd just installed a rebuilt alternator earlier this week and suspect the voltage regulator (alternator) may be the problem. When I turned the ignition switch to the on position, the radio and blower were OK. What checks can I do to make sure its the alternator and not something else?

Sincerely,

Paul