[rec.autos.tech] Unidentified noise from my car stereo.

wolpert@caip.rutgers.edu (Seth Wolpert) (02/09/89)

One of my trusty vehicles, a 1982 Nissan Stanza has a strange noise
coming through the speakers.  It's a hum- sounds like a couple of
hundred hertz, with the following symptoms;

The pitch and loudness never vary (i.e. with engine RPMs).
It only occurs when the lights (parking lights, low beams, or
high beams) are turned on.
It happens with both tape and FM.

Any experiences out there with this type of noise?

Thanks in advance.....SW   >B-}

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carlson@gateway.mitre.org (Bruce Carlson) (02/10/89)

In article <Feb.9.10.32.35.1989.24408@caip.rutgers.edu> wolpert@caip.rutgers.edu (Seth Wolpert) writes:
>One of my trusty vehicles, a 1982 Nissan Stanza has a strange noise
>coming through the speakers.  It's a hum- sounds like a couple of
>hundred hertz, with the following symptoms;
>The pitch and loudness never vary (i.e. with engine RPMs).
>It only occurs when the lights (parking lights, low beams, or
>high beams) are turned on.



Try varying the brightness of the dash lights and see if the noise varies.
My Honda gererates noise from the dash light dimmer if it is set at
anything but full brightness.  I'm now used to having the panel lights
set on full brightness. 


Bruce Carlson

rjd@occrsh.ATT.COM (Randy_Davis) (02/10/89)

In article <Feb.9.10.32.35.1989.24408@caip.rutgers.edu> wolpert@caip.rutgers.edu (Seth Wolpert) writes:
|
|One of my trusty vehicles, a 1982 Nissan Stanza has a strange noise
|coming through the speakers.  It's a hum- sounds like a couple of
|hundred hertz, with the following symptoms;
|
|The pitch and loudness never vary (i.e. with engine RPMs).
|It only occurs when the lights (parking lights, low beams, or
|high beams) are turned on.
|It happens with both tape and FM.

  I have been successful in fixing both alternator noise (which varies with
RPM) and your type of noise by checking and tightening or adding the ground
connections on the system.  Strange how a little simple fix like that can
work....

Randy

wolpert@caip.rutgers.edu (Seth Wolpert) (02/14/89)

Thanks to netters who responded to my plight with the nasty hum
from my car stereo.  As suggested by several respondents, the
problem originated from the dimmer control for the dashboard
lights.  In six years, I had only touched the thing once, and
the radio was not on at the time.  I never would have noticed
it.  I'm sorry I couldn't respond to all who e-mailed suggestions
to me.  Some of my replies bounced.

Thanks again              SW

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