Audio system cutoff

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=69373
Printed Date: July 23, 2025 at 4:38 PM

Topic: Audio system cutoff

Posted By: synchronicity
Subject: Audio system cutoff
Date Posted: December 28, 2005 at 9:41 AM

1987 Pontiac Fiero, the entire system shuts off in this order. Amp and subwoofer, amp and mids and tweets then head unit cuts off.

Rockford Fosgate P4002 to 1 2 ohm DVC 10" Kicker. 4 ohms at amp bridged 400Watt x1

Rockford Fosgate P3002 to Rockford Fosgate Mid and Tweets T162S using supplied crossovers normal settings.

Pair of Infinity 4"x6" 2-way connected directly to Sony CDx-F7000 head unit.

One Farad capacitor to P4002 amp.

Vehicle also equiped with RF-310 Premium Autopage alarm. No bells and wistles just basic alarm.

I'm not having any probelms with the alarm but audio system sysematically shuts off. I've gone thru and checked all wiring and impedence seen by amp and all seem to be wired correct. This is an old car with some wiring issues(door adjar light remains on, parking brake indicates on when it is not). These issues were there before alarm and audio install. New battery is reading 7.5 volts and does not charge, constatly drains. My conclusion is that car needs higher output Alternator and battery post cables replaced. Does anyone agree and is there a test I can do to prove this?

Thanks

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RG

Replies:

Posted By: stevdart
Date Posted: December 28, 2005 at 9:55 AM

That's a tough situation trying to put a sound system into a car that can't hold its own even without add-ons that further tax the electrical system. The car has to be restored to A condition electrically before you can attempt an install (that will actually work). This will include fixing those "little" problems you mentioned. You need to decide, with the help of your neighborhood garage, whether this vehicle is worth the money you will need to spend to get it into shape...including the costs of a new (possibly higher output) alternator, new battery, new and improved underhood wiring, and the labor involved in troubleshooting the wiring harnesses and contact points throughout. There comes a point when you just have to give up on the old girl.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: synchronicity
Date Posted: December 28, 2005 at 1:48 PM

Thanks for the input. This vehicle defenitly has some harness isssues some of which I've managed to repair but your right there is a limit to this madness.

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RG