I have a question about my car or alternator. I have a permanent volt meter inside my car monitoring my electric status due to my audio install, I've noticed that when I'm on the highway at high speed or when at high idle, normally above 2,000 rpm, the voltage drops, below 12.6v and the battery and brake lights start to blink on and off on the dashboard, even with my radio and complete system off. What is happening?

Thanks.

Bump

Above 2k rpm your alternator is shutting off, or some electrical device is drawing tons of current.

 

The first case is more likely. I'd check the connections on the back of the alternator if you can get to them. Do you hear any belt squeal when the voltage drops?

 

More than likely it's time for a new alt.

Something is wrong with ecu maybe. Take to qualified mechanic