smartcraft speedo fluctuating

J

julians

New Member
Oct 18, 2006
126
on the sea
Boat Info
190 sport
Engines
Alpha
Hi all,

Boat is a 2006 sea ray 200 select with the 5.0 MPI with alpha drive fitted with smartcraft instruments.


The speedo has recently started fluctuating up and down rapidly between 15 and 45 MPH even when the boat is stationary . I've tried cleaning out the pitot tube on the out drive, but the speedo still fluctuates.

Any ideas?

Could it be the pitot sensor itself failed? Where is the pitot sensor located on this setup?

Cheers
 
The best idea I can give you for the "DumbCraft Gauges" is eliminate them as they go bad.Same thing with that stupid "Touch Pad System"
 
Julians,

A fluctuating gauge suggests an electrical issue and not the pitot.

Is the speedo the one with buttons on the bottom (system gauge), or without (link gauge)?

There are two ways to get speed on a SmartCraft gauge, via pitot, or via gps.

Do you have GPS? Is it connected to the Smartcraft system? If so check the connections.

If the speed is coming from the pitot, the tube comes through the transom assembly and connects to a transducer located on the inside very close to, or on, the inner transom ring. If you don't have water coming into the bilge, the tube to transducer connection is ok. Check the electrical connections for corrosion, dirt etc. Next possibility is a bad transducer, or the speedo itself. If you have a gps that has NMEA output you can connect that to the SC dash harness (there will be an unused plug for it). The GPS will then send SOG data to the speedo. YO will have to re-configure the speedo, but that is not difficult.

Henry
 
Here's a picture of the pitot, in the position that Henry referenced. This is on a new 200SD, but should look pretty much identical to your boat.

attachment.php
 
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Thanks all for the input.

To answer a few of the questions:-

The guage is the one without buttons.

Its definately running from a pitot and not GPS.

There's no leaking water.

I will try and get to the pitot transducer, its quite tight back thereon my boat, but I guess I should be able to reach it. Thanks for the photo lazy daze.

Does anyone sell a cheap GPS unit that I can hook up to the speedo, something that didn't even have a screen would be ideal. I'm getting fed up of cleaning out the pitot tube every season.
 
To answer my own question, I have found a globalsat br355 receiver on eBay for £30, which apparently outputs the nmea format. I'll also need a 12v to 5v converter, which costs £5. So I should be able to convert to GPS based speed for a total of £35.

That's probably cheaper than a new pitot transducer.

Will find out today whether the pitot transducer really is faulty, and then will order the parts to convert to gps
 
Ok, well here's a spanner in the works.

have just gone into the cal2 menu and there is no option to set GPS as the source under the external sensors section. I just have options for pitot or paddle wheel.

The smartcraft software is v3.04

Anyone got any ideas why I can't see GPS as an option?
 
You have a Link speedometer. According to the Smartcraft product manual, only the System speedometer supports GPS input. I did do some further reading and found that a System speedo will bounce around when it is set for GPS and there is no GPS attached. Makes me kind of wonder if the Link speedo would react the same way if it can not 'see' a speed sensor. Looks like you have some trouble shooting to do in the back of the engine. The good news is the Link speedo is only about 1/3 the cost of the System speedo (USD 100) if it turns out the speedo is bad.

Henry
 
I'm pretty sure its a faulty pitot transducer. If I set the Cal settings to pitot=off and paddle= off, the speed does not move.

The problem is its a major pain to get to the pitot, virtually impossible without dismantling lots of parts of the boat.

I have looked into buying a system speedo so I can hook it up to the GPS, but I'd need a smart craft junction box and some other wiring which ends upcosting a lot.

So for now I'll leave the speed disabled and just use my handheld GPS velcro'd to the dashboard for speed info.

I might get round to replacing the pitot one day.
 
Can you get to it by laying on the engine? I was able to get my hands on it rather easily to move it around for a better picture. Once you cutoff some of the zip ties, it should free it up quite a bit.

If you need to, just pop the gas supports off their studs (takes about 15 seconds) and tie/support your sunpad into a more vertical position. At that point, you should have pretty good access.
 
Its tucked very tightly behind the water trap/gutter that the blower vents through, so really I need to remove this.

I'll have a crack at it next time I get some quality boat time to myself without the family hasslng me (which means it'll prob never happen)

I was looking for an excuse to fit a perfect pass system for wakeboarding, looks like I might have found the perfect reason.
 
julians said:
Its tucked very tightly behind the water trap/gutter that the blower vents through, so really I need to remove this.
Click to expand...

Sea Ray does love their wire loom and zip ties! :smt001 Once you cut some zip ties, it'll get a lot easier. Good luck... when you get that free time!
 
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I had pretty much the same thing going on. It happened just like you described (jumping all over) for about 5 minutes but then went to whatever full speed is and stuck. When the ignition turned off it went to zero and did not do anything when I turned the ignition back on. In my case, I replaced the Pitot sensor and that fixed the problem.

FYI- On my engine, the Pitot is mounted near the spark plug cables. I was told by a Merc tech that sensors and their wires should be located as far as possible from spark plug cables due to interference and potential damage. I think this is true because, ironically all this happened immediately after I changed my cap, rotor and cables. While doign this I mistakingly routed the the spark plug cables to go over the pitot harness when I installed the new plug cables.

After receiveing that advice form the Merc Tech, I made sure to ty wrap the Pitot harness as far away as possible form the ignition componets.
 
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