I'd say that somewhere there's a marginal connection. I'd say it could be the alternator to engine block or block to body, etc. However, if running the extra ground to the firewall did is, that's great. I'm glad you got some resolution.

Steve

 

A fellow member and i were just discussing a similiar alt whine in his truck. He had found that the ground wire on the battery post was the problem. the battery post was actually falling apart from inside the plastic battery case. It was an O.E delco though.

Hmm!

 

Majority of the times that I've seen the problem lied in a bad ground.

 

I know there are a lot of things in this thread you have read to do. But in my experience of professionally installing car audio through the years; I have found that when kenwood decks are teamed with certain amps you have the exact whine problem you are having. I guarantee that if you try another headunit from a friend that is not a kenwood it will disappear. They make a very good product but I ran into this personally on my own truck about ten years ago. I tried everything, then gave up grabbed a new cd 8051 eclipse deck out of our soundroom and everything worked perfect. I was using kicker sub and highs amp as well when my problem occured. Someone here will give me crap about what I just said but do yourself a favor and just try it.

 

Glad it worked out for you. I discovered that a long ground on the head unit is a bad idea when I was competing in SPL comps back in the 90's. We would have our head units on a podium, outside of the vehicle, and would get a nasty humm and motor noise. It was easily cured when we used an additional 12 volt battery in our podium (to only power the head unit) instead of going through a 12 foot umbilical cord back to the vehicle.

As another member mentioned, Kennwood HUs seemed to give us some trouble as well. The best one that we used in comps was always pioneer. For some reason, the signal was always the cleanest. We ended up running only Kenwood as they sponsor dB Drag racing and it is always good to support the sponsors!

 

I know this is an old thread, but in having a pretty bad alternator whine myself. I'd like to try adding a cap. I've googled for a 1000 mFd. I found this:

RadioShack - mobile phones, MP3 players, laptops, and more

I'm not really sure what voltage I need or if it really matters.

 

 

So did the radio shack cap work? Did you just ground the alternator through the cap?

 

Zeake! How have you been? Haven't seen you in awhile.

Ironically, no. My whine wasn't coming from the alternator. It was coming from my sound processor. If it was coming from the alternator, I'm confident this would solve the problem.

 

I think my kenwood head unit is the cause. I guess I will turn the gain on the amp down as I really don't want to mess with it.