Mad-Marcus

Help me out guys,
All of a sudden, I am having additional engine noise through my stereo. It would seem like I lost a ground, but check out the symptoms.

It sounds like a high pitched chirping (like a high pitched motor boat), not the normal ALT whine. It only happens in gear.(auto) In park I can rev and it only whines.(low level of noise)

I checked my grounds at my amps and they all seem tight. This started yesterday and the stereo has been in for months.

I do have a small exhaust leak around the flex pipe that I'm getting fixed tomorrow, but that shouldn't effect it.

If it was plugs or wires wouldn't it happen in park also?


Help!!

jmax

Most likely a ground has come loose or the metal chassis of a component - HU, speaker, processor, amp, etc. - is grounded out. It is odd that it only happens in gear. Another place to look for info on getting rid of noise is the carsound.com forum. David Navone is excellent at this. He's done a lot of really complex installations, like David Crosby's car.

You could start a search by isolating each item in the system to see if the noise is present.

Mad-Marcus

Figured it out after tearing my trunk apart.

My US Acoustic 4085 is mounted on the back wall in the trunk. It is a fairly tight fit, top to bottom. Well bass vibration must of made the mounting hardware loosen enough to allow the amp to slip down. The RCA's are installed at the bottom and were being pinched between the amp and the trunk floor. This either caused pressure on the plug on the amp or on the shield on the cable. I found this while playing process of elimination with all the possibilities. Anyway I moved the amp up tightened everything down and placed a wedge of wood at the bottom lip of the amp to keep it from sliding down again.


Now I'm back to dead silence again!!!!!!

jmax

Glad to hear it was a simple fix.