Seadoo Gauges Problem!. *Tachometer Bumps *Warning Gauges flicker *No Beep. *VIDEO

[oldphones]

This happened after i had done some maintainace (and removed the gauge cluster) i also did some work to the motor.
Here are some videos i found about it:
[video=youtube_share;Pbnz8A3bhG0]https://youtu.be/Pbnz8A3bhG0[/video]

[video=youtube;pCON8VVlV8M]https://www.youtube.com/watch?v=pCON8VVlV8M[/video]

[video=youtube;jJi063POUbw]https://www.youtube.com/watch?v=jJi063POUbw[/video]


My boat in first video. Its a Challenger 230 SE 2008.

There is one beep when i instert the key the first time. Then no moore beeps.

The tachometer bumps and the engine warning light gauges blink.
The Boat operates normally and the fuel level and speedometer works.

What i have tried so far:
*Checked all cables that they are connected.
*Checked all fuses with multimeter.
*Connected Candoo only gives me no error except P0600 code that is said to be caused by Candoo itself.
*Replaced dess post and tried two diffrent keys.
*Checked ground on dess post and gauges.

 

[enut]

I would try to measure the voltages at the gauge while powering it up. You should start with making sure that power and ground are connected with the gauge plugged in. You should get a service manual if you don't already have one.
Let us know how you make out.

 

[oldphones]

Thanks for your input.
What done since i posted is:
*Checked voltage on both gauges when key insterted (12,6v).

I connected both tachometers to external 12v (without key inserted) and they do not jump up and down.
I also connected Candoopro through both diagnostic ports to run engine monitor and rpm working fine in there.

What i read in the manual is that the VCM converts digital rpm signal from ECU to send out analog to gauges. VCM is also connected to the engine warning light gauges.

I think the VCM is borken but i hate to be wrong. This thing costs $900

This is from the manual:

https://i.imgur.com/shc6uCl.png

 

[enut]

Do you have a way to put an oscilloscope on one of the output lines going to the tach? If it is a straight DC analog level, then you may get away with using a voltmeter. Find the output terminals on the VCM going to the gauges. Then I would compare the two signals. If you can take the measurements directly on the VCM, you can rule out the VCM and then focus on the wiring harness/connections.