My stereo power will not go to sleep after after the car goes to sleep, causing overnight battery drain. I am out of warrantee and don't want a $1000-2000 bill from the dealer to diagnose and eventually replace my stereo headunit.

I got an idea from the DIYMA stero forum to add a switch that will turn off the remote power of my system, thus de-energizing my three amps in the trunk.

Instead of a manual switch, which I could forget to activate before leaving the car, I would like to add a spst relay to power this circuit. My question, where in the trunk should I tap into a 12v source to energize the relay? Hoping of course that this source WILL sleep when the car goes to sleep, and turns on when a door opens etc.

thanks,

 

Have your battery tested first, a weak battery will cause a lot of problems, For example if a fan cycles when the car is shut off and the battery voltage drops below a certain point some relays will not shut off, causing the draining of the batteries.

 

Battery is new and good, alternator is good, IBS sensor is brand new. The radio will not go into sleep mode and is draining my battery. I am unable to diagnose further so I am content in cutting the radio's power when exiting the car. I could do it through a switch, but i'd rather turn it off automatically utilizing radio fuse #34 in the glove box. I just need to figure out the best power source for the relay and the bits & pieces to put it together.