Started having trouble with my new used car I bought 5 wks ago. It wouldn't start one night so I got a battery jump and replaced battery next day.2 wks later I won't start again. I wait 30 mins. And it starts. The next day I run errands and it won't start. I wait 15 mins. And it starts but this time it is vibrating. I drive home and it vibrates so bad I can't read the dashboard. What could possible be wrong?