I have an aftermarket headunit that i installed, but the main harness was done by a shop so it was basically just a plug in. The problem is that as i accelerate i have a whining noise coming through my speakers. I put in a new alternator about a month ago and it quit for a couple weeks. Now its back and im not quite sure where i need to start. Any help would be greatly appreciated.

 

ground everything again. especially if you have an amp somewhere.

 

No amp, but ill check my grounds. Thanks

 

+1 on checking all grounds. i had an amp that did this same thing once sent engine noise through my sub, ended up being a bad ground. do you have the factory bose speakers? If so a lot of times when aftermarket h/u's are installed the bose speaker amps are bypassed (bose speakers have individual amps on the back of each speaker unlike other speakers that get power from the head unit itself), could be a problem there.

 

Hi, I know all about stereo's I have won a lot of competitions in my truck. If the ground
wire does not do the trick, try going to your local stereo shop and get a noise filter for your hot wire!

 

personally i'd recommend rewiring those stock speakers if you use an aftermarket head unit... more than likely its all running on different ohms. mine was giving me all sorts of trouble until i replaced all the door speakers and wiring.