2003 4.3L Mercruiser Tachometer not working?

Z

zanezwerenz

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I have read through all the posts and have not quite found the answer to my issue. Sure hope someone might be able to provide some suggestion to fix my problem.

I have a 2003 4.3L Mercruiser I/O and my tachometer is stuck and sitting at 2000+- rpms. My needle will NOT go to zero when I turn the key to the on position and it stays there regardless of engine RPM's. I have taken the boat out on the lake and it runs perfect. No miss firing or problems starting. Tach worked perfectly before it was winterized last Fall.

Any help would be appreciated.

Thanks

Zane
 
U

Uraijit

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Re: 2003 4.3L Mercruiser Tachometer not working?

Sounds like a problem with the gauge itself to me...
 
Z

zanezwerenz

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Re: 2003 4.3L Mercruiser Tachometer not working?

Any way to test to verify it is the Tach that is bad?
 
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Uraijit

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Re: 2003 4.3L Mercruiser Tachometer not working?

If it's not zeroing with the key off, it's almost certainly the tach itself. The tach works based off of pulses from the coil, rather than reading a voltage, so it's not going to be a problem of a short, since there's no pulse coming from anywhere else. If you want, disconnect the wiring from the gauge just to be sure...

You don't have a battery charger hooked up to anything, do you?
 
Z

zanezwerenz

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Re: 2003 4.3L Mercruiser Tachometer not working?

Uraijit said:
You don't have a battery charger hooked up to anything, do you?
Click to expand...

No, I do not have a charger hooked up to anything. I will clean all connections and then check and see if I'm getting voltage to the "I" terminal on the back of the gauge as well as make sure the "G" terminal is grounding correctly. If both are good I will suspect I have a bad tachometer correct? Could it possibly be anything else?
 
D

Dakota47

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Re: 2003 4.3L Mercruiser Tachometer not working?

Yep Bad tach. might be the sender too. i would change them both.. cheap & easy. :cool:
 
C

Coors

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Re: 2003 4.3L Mercruiser Tachometer not working?

zanezwerenz said:
No, I do not have a charger hooked up to anything. I will clean all connections and then check and see if I'm getting voltage to the "I" terminal on the back of the gauge as well as make sure the "G" terminal is grounding correctly. If both are good I will suspect I have a bad tachometer correct? Could it possibly be anything else?
Click to expand...

Google boat tach problems
 
Z

zanezwerenz

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Re: 2003 4.3L Mercruiser Tachometer not working?

OK guys, here is the status..

I pulled the Tach out last night, cleaned all contacts and put back together. So now when I turn the key to the on position the needle moves but not always the same amount. When I start my boat it seems to work at idle, but when I rev the motor past 2500 RPMs it stops and once the RPM's drop back down below the 2500 RPM's the needle goes back down. Its almost like the tach is sticking when RPM's are past the 2500 RPM mark. I have tapped on the gage to see if I can loosen it up past 2500 RPM, but no luck.

So the question is does this sound like the tach is bad or could it be the signal from the coil stops sending after a certain RPM?
 
Don S

Don S

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Re: 2003 4.3L Mercruiser Tachometer not working?

Put a new tach in it.
 
Bondo

Bondo

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Re: 2003 4.3L Mercruiser Tachometer not working?

So the question is does this sound like the tach is bad
Click to expand...

Ayuh,......

Sure Does.......
 
Bondo

Bondo

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Re: 2003 4.3L Mercruiser Tachometer not working?

Ayuh,......

Right here at iboats,..... If they have'em......
 
JustJason

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Re: 2003 4.3L Mercruiser Tachometer not working?

Tach sender.... hehehe... thats a new one.
I think mine is mounted right next to my dilapidator valve.
 
Z

zanezwerenz

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Re: 2003 4.3L Mercruiser Tachometer not working?

Fixed the issue... BAD TACHOMETER! Replaced with new and working perfectly. Thanks for all of your help.

Zane
 
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