battery drain after new head unit

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=109406
Printed Date: May 12, 2025 at 2:51 PM

Topic: battery drain after new head unit

Posted By: keevel
Subject: battery drain after new head unit
Date Posted: December 02, 2008 at 12:11 PM

Greetings all:
I have installed a Pioneer DEH-P77DH in a '02 Suburban with OnStar. Since the install, there is an apparent drain on the battery w/o the ignition turned on (aux or run). Alternator output is normal (up to 30+ amps depending on battery voltage). Is there a way to check battery discharge when all is shut down? There was a relay included in the wiring harness but I don't see where the drain can be with everything off.
-keevel posted_image

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"If you want an education, go to the library. If you want to get laid, go to college." -Frank Zappa

Replies:

Posted By: dwarren
Date Posted: December 03, 2008 at 1:09 AM

Did you retain onstar? If so what interface did you use?

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Posted By: keevel
Date Posted: December 03, 2008 at 12:39 PM

Thanks for the reply. The owner wanted to retain on-star capability but he is not currently a subscriber. I used the PAC OS-1 interface. I sort of figure this has something to do with on-star in that every time the battery drains to nothing (< 9 volts), once a charged battery is applied, the 9 pin harness to the OS-1 has to be unplugged and reconnected before there is sound to the speakers.

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"If you want an education, go to the library. If you want to get laid, go to college." -Frank Zappa