Tach doesn't register on vortec 6.0?

[2Driver]

Just noticed the Tach is not registering on my 6.0 vortec marine power. The Tach has power and the needle bumps a hair when the engine is started but it doesn't register. The hour meter in the Tach is on but not counting time.

I found this wire hanging off in the rear top harness. Could it be it?

 

[2Driver]

I guess i should put this in the lounge for attack ?

 

[JBS]

I am going to say that wire is not for the tach. On the newer Merc stuff the tach comes out of the main harness the same as the other gauges from the PCM

With that I am about out of knowledge. :rolleyes

 

[2Driver]

I am going to say that wire is not for the tach. On the newer Merc stuff the tach comes out of the main harness the same as the other gauges from the PCM

With that I am about out of knowledge. :rolleyes

Thanks.

Its a Marine Power for a jet set up not a Merc. It had just come back not too long ago from a routine service. I wonder if they disconnected something and didn't put it back. Shit I hate to drag this somewhere to be corrected if its something simple.

 

[Outdrive1]

Should be a grey wire. That's the standard color for the tach signal wire.

 

[Outdrive1]

There should be a grey wire in your harness. If you are running a coil, it should connect to the coil after the point where the harness plugs in.

 

[2Driver]

There should be a grey wire in your harness. If you are running a coil, it should connect to the coil after the point where the harness plugs in.

Its a stock 2004 Chevy 6.0 Vortec EFI from Marine power. Maybe I should just go get it scoped so I can get a true hour on the motor and adjust the gauge accordingly. Fock me, who can do this in Parker or Havasu without leaving the boat over night?

 

[Outdrive1]

Does it have a coil or individual coil packs for each cylinder?

If it has a coil, run a wire from the negative side if the coil to the tach temporarily over the interior. If the tach works, then either run a new wire along the harness, or start by bypassing the connections and or plugs in the harness.

 

[2Driver]

Does it have a coil or individual coil packs for each cylinder?

If it has a coil, run a wire from the negative side if the coil to the tach temporarily over the interior. If the tach works, then either run a new wire along the harness, or start by bypassing the connections and or plugs in the harness.

LOL its one of these thingys . http://www.marinepowerusa.com/jets_6.0liter.php

 

[JBS]

It has the MEFI system. The Rinda code reader will work. Most shops should be able to help you


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[2Driver]

Well any fresh ideas?

I took the boat to Prestige marine and they said the tach was getting a signal and power and to replace the tach. I bought a brand new Faria ( same as stock) installed it and nothing

Same thing. Hour displays and it lights but hours don't move and needle doesn't budge.

 

[jetboatperformance]

Well any fresh ideas?

I took the boat to Prestige marine and they said the tach was getting a signal and power and to replace the tach. I bought a brand new Faria ( same as stock) installed it and nothing

Same thing. Hour displays and it lights but hours don't move and needle doesn't budge.

What ignition system ?, some tachs an some systems are not compatible also if the tach has a dip switch on the back where is it set ?

 

[2Driver]

What ignition system ?, some tachs an some systems are not compatible also if the tach has a dip switch on the back where is it set ?

Thanks. Its the same exact tach and the dip switch ( in this case a dial) is set for 8 cyl.

I just called Marine power and they were very helpful. They said the tach driver is not sending the signal and i guess it's not an uncommon thing to happen. They have a service bulletin for the work around ( dated Nov 28 2011) so you dont have to buy a whole new $1,000 MEFI.

The work around is moving the tach wire to another place on the ecm connector and making one splice into the tach wire from another wire coming off the ecm . This is for a MEFI 4 a or b. We are going to try it.