Helped a friend of mine put in an Alpine radio today,and now there is a pop/clicking noise coming through the speakers when you turn the volume up/down or hitting the preset station buttons. I took out the radio and hooked the monsoon hu back up and the problem was gone. Checked all wiring and re-installed the Alpine and the noise is back.Any opinions?

 

It's something to do with the Alpine head unit, it might actually be a "feature" such as those annoying beeps that are on some decks, check the manual to see if there is a way to disable it, if not, then check with the place where you bought it to see if you can exchange it or if they will test it for you.

HTH