Thread: Problems after Installing Amplifier and Subwoofers

First off, I drive a 2001 Pontiac Grand Prix GTP Supercharged.

I recently installed a Sony Xplod amplifier (1100W Max) and two Sony Xplore 12" Subwoofers. I installed these on a stock radio using a line level converter (hi-lo converter, etc.) to splice into the positive and negative speaker wires in the rear deck of the car. I ran the power wire to the battery, grounded the amplifier to a metal nut and bolt on the frame of the rear speaker deck and finally ran the remote wire to the fuse panel and used an add-a-circuit to tap into the Radio fuse so that the amplifier will only turn on when the radio is on. I do not run my radio when the car is not running and it is not a very powerful amplifier or subwoofers for that matter.

I started getting weird problems after doing this (my car was behaving just fine before this). Everything runs fine until I try to turn the air/heat on. When flipping the air/heat on my Boost Gauge Display will turn off completely, the air/heat will not work, and my daytime running lights will turn off and then proceed to turn off and on over and over again but very slowly. My air will go on when I crank it up to speed 5 but everything else will stay off.

I also have three other things wired into my fuse panel (if it is important to solving this issue), they are small 12v accessories, two sets off interior led tubes, and an fm transmitter. These all have switches and are turned off when the car is off.

I suspect either a wiring issue or battery/alternator issue. If anybody has ever had this issue after installing an amplifier, please help!! Looking for anything that will help!

use a multimeter to test the battery/alternator with the load off and on and check your grounds.

what exactly did you ground on the speakers? the speakers (+) and (-) should only connect to the corresponding (+) and (-) from the amp (floating), speaker connections should not connect to chassis at all.

^ I assumed that was a typo....

I was gonna suggest the ignition switch as the problems you have described are all indicative of an ignition switch going bad. Replace it and you should be golden.

ive found far more ign switch failures in high switched load cars....so yea aftermarket crap does add to the draw and increase the wear and tear.

as a mech I noticed a lot of the failures are high switched loads...ie key is switched with fan/wipers/ac/wideband on and you get a higher current draw at the ign terminals besides the usual. extra current leads to greatting contact pitting. switch off components before turning the car off and yourd probably extend its life by at least a 1/4

using the oem ign to switch a honest to goodness 30-40 amp high quality relay is the preferred fix for this issue which spans many manufacturers and cars