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Tachometer Whine

March 18, 2017, 01:15:04 pm

Since I brought this one home I've noted a faint high pitched whine from the dash. In my quest to fix another issue I finally discovered that it is the tach. Turn on the ignition and the whine commences. Remove the ground from the tach and it stops. The tach works fine, has the proper voltage and the ground wire is good. Any ideas on what might produce this annoying sound? Thanks.
jor

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Re: Tachometer Whine

Reply #1 – March 18, 2017, 01:22:08 pm

Maybe related to your snipped wires?

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Re: Tachometer Whine

Reply #2 – March 18, 2017, 03:36:23 pm

Jor,

Sounds as though you've been spinning your wheels.  (sorry, just couldn't resist)

Jim

2002 U320 42'

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Re: Tachometer Whine

Reply #3 – March 18, 2017, 05:07:21 pm

Wonder if the sound is from the pulsing signal wire.  Since ground removes power and stops the sound, I assume removing the 12v + wire will also stop it.  But will the sound go away when Tach is powered with a good ground and hot wire, but without the signal from the back of the engine.  If so, maybe the tach signal sender wire is loose?  Sender is a magnetic pickup on the upper side of the engine to transmission bell housing.  Try removing the wire at the bell housing, too to diagnosis.  Even though sound seems to be from Tach, could it e from something else?  Use a hose to your ear with open end touching things to isolate the source.  Maybe alert buzzer?

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Re: Tachometer Whine

Reply #4 – March 18, 2017, 05:19:31 pm

Does the tach have the hour meter built into it?

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Reply #5 – March 18, 2017, 07:07:36 pm

I have a whine when I turn on the headlights... Dim the dash and it goes down.. Its through the speakers.. then there is this other whine I have but she has been with me for a long time 24yrs so she stays... kinda tone deaf now to it.. the second whine not the first 

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Re: Tachometer Whine

Reply #6 – March 18, 2017, 08:00:03 pm

I've had my whine for 50 years, I'd miss it if it went away😀

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Re: Tachometer Whine

Reply #7 – March 18, 2017, 08:59:50 pm

David and Robert,

Please post pics of the bruises and marks left by the DW's after

they ready the posts !

Carter-

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Re: Tachometer Whine

Reply #8 – March 18, 2017, 09:38:51 pm

My DW is computer illiterate, doesn't even know how to turn it on. I could get away with anything I post.

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