Immediately shuts off when turn on.

check the wires to your amp.may be a broken earth wire.

Check this on 1999 Pontiac Bonneville Car Stereo Wiring Diagram, could help...


Car Radio Battery Constant 12v+ Wire: Orange
Car Radio Accessory Switched 12v+ Wire: Yellow
Car Radio Ground Wire: Black
Car Radio Illumination Wire: Gray
Car Stereo Dimmer Wire: Brown
Car Stereo Antenna Trigger Wire: Pink
Car Stereo Amp Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: 4" x 6" Speakers
Car Audio Front Speakers Location: Doors
Left Front Speaker Positive Wire (+): Tan
Left Front Speaker Negative Wire (-): Gray
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Dark Green
Car Audio Rear Speakers Size: 6" x 9" Speakers
Car Audio Rear Speakers Location: Rear Deck
Left Rear Speaker Positive Wire (+): Brown
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Dark Blue
Right Rear Speaker Negative Wire (-): Light Blue

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

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Loose wire or connection is causing stereo to short out, Check all connections including amp,Stereo,Speakers and make sure nothing is touching places it shouldn't

That message means the audio amplifier IC´s are damaged

You may have overloaded your audio output with the external speakers(impedance or short wire problem?)as a result the audio out i.c maybe damaged which in turn may have blown one of several fuses in the power supply.maybe regular GMA type fuse or picofuses,you can try replacing blown fuse but if they blow right back you`ll need the help of a repairman

unplug the system.take out any extra speakers,and try plugging it back in.

The wires may have gotten wet and fried something in the sound output in the stereo.

If the unit shuts down almost immediately without sound, you have an electronic failure of the audio amplifier.

However if you must play the unit up above quiet background levels, you likely have a shorted speaker wire. With home theater systems, you have the luxury of trying different surround modes and speaker level settings. It's not unusual, for example, to have a loose wire strand going to the center speaker. In stereo, the system works fine. As soon as you switch to a surround mode, the amplifier senses the short and shuts down to protect itself.

Check those wires really close - I bet you'll find it there.

sounds like the ohm load of your speakers is incorrect and overloaded the amp,....check all your specs, i.e. max, min ohm load on stereo, and speakers,...this stuff is important and must be within the range allowed or stuff like your experiencing happens,.....it's happened to me before,.....fried my amp because i had house speakers in my van, was great for about 3 loud days,....good luck, cracklin joe,.......

This maybe an easy one. Have you unhooked all the wires going in to the stereo. "SP wires" means you have wires to the speakers are touching and the stereo is shutting down to avoid overloading. Hope this helps...