I have an Alpine V Power MONO amp and when i sit in one place with the truck turned off.....and the system runnin, my amp will cut off after a few minutes. But it only does it when the truck isnt runnin. I think its because my battery is dropping below12volts and my amps has to have 12 volts goin in to power it. What should I do. I have a cap but should i hook it back up? Or will that help?