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Tach problem

Ljapilot

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Hello Everyone,

First let me say awesome forum. You guys (and gals) are a great source of info. Put most my fears to bay before we purchased our first boat.

Well we have our first issue and was hoping y'all could help.

When we first purchased the boat the left tach oil pressure light was not working. Had a new tach installed but mechanic says rpm only shows intermittently. He seems to think it might need an ECU on left side. We took it out today and here is what I observed. Rpm for either engine does not show until second engine is started. Start right or left first doesn't matter. Neither Tach shows rpm until second engine is started. Could this be an ECU issue? Doesn't seem like it to me.

Any info/advise would be appreciated.

Here she is. I know everyone likes to see pictures.
 

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Bruce

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Sounds like a key switched power supply issue to me. I believe all the key switched power wires are purple. I would look for a loose one behind the dash.
 

Scottintexas

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glad to have you on board, who is your mechanic, a dealer or independent? Did he hook up a YDS to check the information coming from the ECU's ?
When your tach's are working are they showing different rpm's when you work the throttles? Does the boat run fine otherwise?
 

Gym

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@Ljapilot. I doubt this is an ECU issue. I had this same problem on my 06 SX230. It was a corroded pin in the connector located in the starboard aft locker where most of the wire harness are lcoated behind a wHite plast ic plate wit 6 screws. There is a 9 pin connector for each engine. The red wire is for the tach. I believe you will find corrosion or water ca using your problem. I removed the red wire from the male & female side of the modular connector and used a heat shrink connector to bypass the modular connector.
 

Ljapilot

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Scottintexas

It is a dealer. Yes they hooked up the cables and did not find anything they said. Once both engines are started tachs read accurately. No other issues. Run great. Ran her for over an hour today.

Gym

Thank you. I will look at that this Sunday/Monday when I head back to the lake.

Thanks for all the help.
 

itsdgm

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Welcome aboard @Ljapilot glad you found us and decided to join. I can't imagine that this is an ECU problem at all. Every ECU problem that I've read about has been related to engine performance issues. I'd bet money that @Gym 's issue is what you're having. It might not be the exact plug that his was, but something similar. Good luck with the repair, keep us posted.
 

Scottintexas

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If the YDS read the correct rpms and isn't showing intermittent readings then you know it's not the ECU because that's where the YDS is getting it's info from.

It worries me that they would suggest or think that it may be the ECU, could they think your an easy mark and hey, you need a $1,500. ECU to fix this.

Neither tach showing a reading until the second engine is started is very confusing and sounds like a key switch wiring issue that Bruce suggested above, intermittent readings sound like Gym's idea,

Since this is a new to you boat their's no telling what the previous owner might have done.

Whatever the issue the YDS says the engines are running fine so I wouldn't let this slow down my enjoyment of the boat, learn to live with it or just take your time and track this gremlin down.
 

itsdgm

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@Ljapilot out of curiosity does your boat have Perfect Pass or any other upgrades? Also, do you know any history on the boat? Would it be possible to contact the previous owner to get the history of the issue?
 

Ljapilot

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Itsdgm

No it does not have perfect pass or any other upgrades I am aware of. This was not an issue until they replaced left tach for oil pressure light. Before the tach was replaced both worked on initial start up. Yeah confusing I know.

Scottintexas

Don't think they are thinking I'm an easy mark since they are footing the bill for this known issue before I purchased it.

Im not that worried about it but since they are footing the bill I would just like it fixed correctly.

Bruce

Thank you for the advise. Sorry I did not thank you in my second post.
 

Bruce

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I would be checking the wiring to the tach that was changed.

If you take the screws out of the panel that the tachs are mounted in you can pull that panel forward and get a good look at all the connections. I have done so many times. The wires are long enough to have good access.
 

Scottintexas

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I would be hesitant to let them work on my boat any further if they thought the ECU was causing this issue. You may get a new ECU but what else might they screw up along the way and what about when the new ECU doesn't solve the problem, they're still searching
 

Julian

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I wonder if they somehow swapped the plugs either behind the dash or back behind the plate where the YDS connects (which on a 2007 is behind the white plate in the engine compartment starboard side). Are the tachs showing the rpms for the correct engines?
 

Ljapilot

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Julian

The tach are reading correctly and proper side.
 

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Julian

The tach are reading correctly and proper side.
So it might be possible they did a double swap....behind the dash they are swapped, and as a result the power to the tach isn't being delivered, and at the same time if both engines were started they'd both work but be reversed, and to correct the reversal, they swapped the connections behind the access port where you connect YDS. (this is a stretch, but would perhaps give you the symptoms you are seeing).
 

Murf'n'surf

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Switch the gauge plugs at the YDS connection and see if the problem moves to the other tach. If it moved your issue is the plug itself or upstream towards the ECU. If it stays the same look at your tachs wiring.
 

Evan Meade

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My tach, speedo, gas gauge, etc are not working. Power everywhere else except nav/anchor lights. All wires at the back of the gauges are snug. Wiggling did not help. I note there is an extra square grey quick connect laying inside insturment panel area. Boat in storage 2+ years but everything else working fine. Anyone have schematic? Ideas? Help!
 

bronze_10

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Most often in the beginning of the season when this issue comes up people miss a wire when reinstalling the batteries. Did you remove the batteries for the winter and put just put it back in? I know I have done it and so have many others here..
 

Scottintexas

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@Evan Meade glad to have you on board, a picture of the loose connector would help, I would agree with Bronze about checking your battery connections also maybe you have a blown fuse?
 

Evan Meade

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I checked the battery and everything appears to be connected properly. After checking the battery and wiggling the small black wire connected to the negative terminal, the navigation light started working. There is a single, heavy gage battery wire connected to the positive terminal. I do not see any other, smaller red wires that might connect to the positive terminal. Unfortunately, the tach gauge does not work. I also note that it does not back light light with either the nav or courtesy lights on. Pics of plugs laying in area behind gauges & switches below.IMG-0700.JPG IMG-0701.JPG
 
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