Hey Guys, (and gals);
When I got my Conv Z32 there was a Sony Xplode headunit, I swapped it out with a JVC Headunit, and connected an amp in the trunk to the installed rear speakers (anyone who doesn't know, Conv didn't have rear speakers, so I installed my own 6X9's on the rear shelf).

Here's the issue... when I mute the unit, I'm hearing engine feedback through ALL the speakers in the form of a high pitch squeal, affected by RPM's. What the Hell!!! I double checked the ground to the amp, and it's good: 0.01 ohms in a 2.5 foot run of wire.

Anyone have any ideas?

The Not-So-Funny thing is... My Grand Cherokee is doing the same thing... I'm getting so frustrated with this mess... I love listening to music, but when I have to mute the system, I HATE hearing engine Squeal. It's so annoying!!!

H E L P!!! Please?

 

You can try larger ground wire and install a filter. Did you use an isolated ground? Did you remove any paint from the grounding point?

Did you run the ground wire on the opposite side of the car from the power wire? You can pick up noise if they're run on the same side of the car.

Did you use cheap wire?

 

It's just a capacitor/inductor (good ones) cheap ones are cap/resistor, when hooked up together they make a tuned circuit. Tuned just means that at a certain frequency will charge up the capacitor and discharge through the inductor at a frequency above or below human hearing so you wont be able to hear that annoying hiss or whine from the engine revving up coming through your speakers.

Here's a web site for all your chokes/filter needs.

http://www.autosound2000.com/filters.html

 

The Ground is only a 2.5-3ft run of wire so therefore it is NOT running with the power. The Ground for the Amp is isolated and i removed all the paint at the grounding point. I also ran the A/V cables seperate from the power wire. Still doing it. The wire is high quailty wire. I try my best NOT go cheap on stuff like that.

I'm thinking a filter of some sort is what I need, but what type...

 

It's not your ground for your amp.
It's your signal wires/RCA cables feeding your amp.
try this, disconnect them from the amp. I bet your alternator whine disappears.
Your cables are picking up the noise from somewhere between the head unit and the amp. Back track the cable and move it away from any power sources that includes the amp turn on lead. Signal and power shouldn't cross at any point and if you have no choice but to cross them, try to do so at a perpendicular angle, i.e. 90 degrees.

Moved to 300ZX (Z32) Appearance Exterior, Interior.

 

is talking about is ground loop interference. They also make filters for that. Its caused by different "ground" voltage between interconnected audio components.