Hello, I have a 2006 Trailblazer EXT. I have a buzz on the radio all the time and I was wondering if you can still just add a capacitor to the alternator or is there something else that has to be done?

 

Before you go messing with the alternator or radio, I would suggest first ruling out a blown speaker. The speakers in these vehicles are barely worth the name speaker. They are some of the cheesiest pieces of junk ever foisted off upon the American motoring public!
Using the fader and balancer, send power to only one speaker at a time and see if the buzz goes away.

 

Hello flyboy2610, I went out and tried what you suggested. I did find one speaker with a little rattle but, the engine wine was still there. The wine would change tone with the speed of the engine. I changed the spark plugs just in case they were bad but still there. I am going to replace the radio and front speakers I just want to make sure I get rid of the wine before I go through all of that. Thanks for the reply if you have any other advice it would be greatly appreciated.