update on alternator noise over speakers

[Mark L. Chang]

On Fri, 8 Dec 2000, Tim Sidders wrote:

> I have disconnected the RCA's, and the noise goes away....These are $40.00
> Rockford Fosgate cables which are supposed to be very good. I guess this is
> telling me that the problem lies in the RCA's, maybe if I move the remote
> turn-on so it doesn't run along the RCA's this may solve my problem.....

This doesn't tell you that it's the RCA's fault. All it says is that the
wiring to the amp is probably okay. You still may have noise in the
headunit that is getting transmitted (as it's supposed to) down the RCA
cables.

Some rules of thumb:
1) route power/gnd away from RCA cables, preferrably on opposite sides of
the car
2) make a nice clean power/gnd connection at the head unit supply, because
that is where you signal originates and you want it to be happy
3) your remote turn-on is not causing noise. It is negligiable current and
is steady-state at +5v. Lots of RCA cables for cars have the remote
turn-on lead integrated into the jacket of the RCA cable because it is not
a source of noise.

More often than not, in my experience, it's an unclean/noisy GROUND at the
head unit that causes a lot of the noise.

--
Q:      How many surrealists does it take to change a light bulb?
A:      Two, one to hold the giraffe, and the other to fill the bathtub
         with brightly colored machine tools.