Expert: Ernesto R - 5/28/2006

Question
Hello! My wife has a '97 grand am gt that has the orig. GM am/fm/cass. player in it.  A few years ago I installed my jensen cd changer in the car.  It used an rf modulator.  Sound was fine except for 2 things.  

When you hit pause, you could hear a fast-paced high pitched swishing or spinning (from the cd spinning?) noise coming through.   Turn the volume up  and it gets louder.  The noise is not alternator noise.  It is constant and only changes in loudness when you increase volume.  

I thought that since the changer was old, that might be the culprit.  I just got a new sony 565 w/ rf modulation and guess what?  Same thing!  

I did some messing around with everything.  The changer is definitly grounded well.  I have it hooked up to a big bolt that holds the spare tire and goes right to the trunk floor.  I did try other grounds but the problem persists.  When I unhook the modulator, the sound is gone. Tape play is normal.  The head unit is still grounded through the factory harness.  Should I cut the old ground and make a clean ground myself?  Could an antenna filter be in order hear.

As one more note.  I hooked up my old jensen in my jeep(which has a new xplod HU in it and all good grounds) and there is no noise like in the car.

This noise is driving me nuts!  Thanks for any help you can provide!  

Answer
the problem can be on the fm tunner of your delco radio
the sensitivity change on the tunner and is getting the noise from the laser of the changer this is normal and it is always there on almost any cd changer or cd player  but the tunner don't have to receive this signal

some delco radios have a source or aux button  if you have that look for a 9 pin plug in the back of the radio that is the cd changer plug or aux audio input  you can plug the cd changer that wAy NO fm modulator the noise will be gone and the sound quality a lot better