Alternator whine in Dual Radio

runcool · 02-29-2008, 07:46 PM

I have two Dual radios. one old and one new.
I have a 2001 Nissan Altima Special Edition with built in Window antenna. **I have physically checked for broken wires in that spot to. It is working normal according to the specifications stated in a special manual that I have**
Both Radios use the SAME hardness, so no need to change it out again and risk messing it up. **I have rewired everything again anyway to troubleshoot this issue but it didn't change it issue**
With the old Dual radio, I have no issues at all in any form or way.
When I installed my new HD Radio from Dual, my alternator started whining.
My first thought was maybe something wasn't wired right. So I got my nice Multimeter out and tested ALL wires correctly. **I have a two year Electronics Computer Technology degree. so I think I can test a few wires. lol**
I did notice an issue right off. The ground on the harness that I bought is not grounded to anything. It is basically a fake wire that goes no where to the car. I researched this and found that all harnesses for my car are 100% the same. On my car, the radios are grounded through the antenna. So, I thought hmm maybe I should attempt to wire that ground from the radio to a real ground. So I did and the whine only got worse. OH SORRY FORGOT TO SAY, the whine doesn't happen to at least where I can hear it when the power on the radio is off.

I unplugged the antenna and left it grounded to the car and the whine stopped completely.

So, my real question is... Is there something that I did wrong or is the radio itself the real issue here? I've brought this up before but only got smart *** remarks by people that didn't have any idea or didn't read what I had to say. I gave up on this issue because it was too cold outside. But now it is getting warmer... I'd like to fix this issue once and for all.

runcool · 03-02-2008, 03:04 PM

Error23 · 03-02-2008, 03:08 PM

Sounds to me like the ground loop is coming from your antenna not the radio...

runcool · 03-02-2008, 03:48 PM

There is a 10K resistance in the antenna. That is measured. thanks for being the ONLY person in months to even notice that. It's sad that people don't know how to think outside the box.
Now the question is.... Why would an antenna be grounded? could I ground the unit where it is supposed to be grounded and fix the issue.**this didn't solve the issue when I did it** The antenna is in the window

Error23 · 03-02-2008, 04:01 PM

The antenna shouldn't need to be grounded, but it sounds like a ground loop (from somewhere) is traveling through the antenna to your radio. I would trace the antenna wire to where it reaches the window and look for any tears where electrical noise (from any other source) might could come through the antenna...

pancit175 · 03-02-2008, 06:53 PM

Does it only happen when you are using the radio or when you are using the CD as well.
Nissans are notorious for not grounding through the harness and only through the chassis.

In my opinion, The problem may be the fact that you did not properly ground the radio properly, initially, that the radio was using a floating ground and damaged the radio or grounding through the antenna and damaged the antenna. The problem with grounding through the antenna is the fact that because of the resistance, it is not meant to be used as a ground for any electronics, only as a means for a reference for the antenna signal. So the possibility is you may have to change out your radio or the entire antenna, antenna amp, and/or lines.