I have an '07 Tahoe with Bose and Factory Rear Seat DVD system. I get "alternator whine" coming through my back speakers but only on an intermittent basis. I found some really helpful posts on this forum leading to me believe I likely have a bad diode in the alternator or a ground wire issue. I'm not sure where to go from here and am considering just replacing the alternator but thought I would provide a few points to see if any of you would have a suggestion on next steps:
1. The whine typically occurs when I first start driving the vehicle after it has sat overnight or for 8-10 hrs. It typically only lasts 30 seconds - 2 minutes and then everything is fine.
2. The pitch changes with engine revs (higher pitch with higher RPM)
3. If I turn on the rear seat DVD (which cuts power to the rear speakers) it goes away instantly
4. If I turn the volume all the way down to zero, it goes away...if the volume is turned down low but not all the way off, I hear the whine...basically if I have any volume the loudness of the whine does not change. I can hear it plainly at normal listening volume.
5. This has been happening for 12-18 mos but seems to be getting progressively worse lately (it happens more frequently and lasts a bit longer).
6. The ONLY aftermarket equipment on the vehicle is a Scosche ipod interface that plugs in between the XM and onstar boxes. I didn't have to splice or cut or ground this...it plugged in with no additional wiring. I installed this in early '07 and had no whine for 3.5 - 4 yrs. I'm thinking about taking this out just to completely eliminate this from the equation.
Any ideas what I should try? Remove the Scosche interface? I also thought about starting the truck in the morning and then unplugging the alternator when the truck is running and speakers are whining to see if it goes away....is this a horrible idea?
Any advice would be appreciated...this is driving me nuts!!
Thanks!
keith
1. The whine typically occurs when I first start driving the vehicle after it has sat overnight or for 8-10 hrs. It typically only lasts 30 seconds - 2 minutes and then everything is fine.
2. The pitch changes with engine revs (higher pitch with higher RPM)
3. If I turn on the rear seat DVD (which cuts power to the rear speakers) it goes away instantly
4. If I turn the volume all the way down to zero, it goes away...if the volume is turned down low but not all the way off, I hear the whine...basically if I have any volume the loudness of the whine does not change. I can hear it plainly at normal listening volume.
5. This has been happening for 12-18 mos but seems to be getting progressively worse lately (it happens more frequently and lasts a bit longer).
6. The ONLY aftermarket equipment on the vehicle is a Scosche ipod interface that plugs in between the XM and onstar boxes. I didn't have to splice or cut or ground this...it plugged in with no additional wiring. I installed this in early '07 and had no whine for 3.5 - 4 yrs. I'm thinking about taking this out just to completely eliminate this from the equation.
Any ideas what I should try? Remove the Scosche interface? I also thought about starting the truck in the morning and then unplugging the alternator when the truck is running and speakers are whining to see if it goes away....is this a horrible idea?
Any advice would be appreciated...this is driving me nuts!!
Thanks!
keith
