Trim sensors on 310da

[Coz]

My trim gauge pops up in vessel view periodically even though I’m not adjusting the trim. Is that common?

Also, what does the trim limit switch do? On my old boat, the trim limit switch would shut off the trim pump to keep you from trimming too high while under power. You could override this if you wanted to put the drives in the trailer position.

This boat doesn’t have an override and the trim never shuts off as long as you hold the button.

 

[pyro]

I assume it is the sensor starting to fail since it is giving ghost triggers to vesselview. I can't speak to how common it is, but these sensors are notorious for failing (usually the wires). I think I am installing replacement #3 on a 10 year old boat. ALways has annoyed me that MerCruiser can't select a suitable wire insulation material for the application.

Do you have smartcraft gauges or what people call analog gauges, meaning analog input gauges? Older boats had an analog trim sender and a separate trim limit sender. At some point they started making a digital sender which hooked up to the smartcraft system. If you have smartcraft gauges then it would get the digital data from the digital sender. However some boats still had analog input gauges for trim, even though the engines were technically smartcraft compatible. So these boats have both analog and digital senders. On my 2008 290 the wiring diagram shows that the analog sender gets wired into the engine harness, goes through some harnesses (a bit unclear in the wiring diagram) but then shows it is ultimately non-connected.

I am attempting to order the digital only trim senders instead of the digital & analog which is technically the correct part for my engine but for 2x the price. I will update my thread on the results next week:
http://www.clubsearay.com/index.php?threads/trim-senders-digital-and-analog.92141/

I don't know the answer on the trim limit. Properly calibrated (through smartcraft) 0-10 is trim while underway. 11-25 is "trailer" position. Analog sensor would have to be calibrated manually using the trim ram measurement method.

 

[Coz]

The mercuiser parts diagram shows I have 1 digital (3 wire) and 1 analog (2 wire) sensor on each drive which I confirmed by inspection. My dc wiring diagram shows a trim limit switch (2 wire) on each drive wired to the trim pumps. My smartcraft diagram shows a trim switch on each drive (presumably the digital 3 wire).

My trim pumps do not shut off automatically, so either my limit switches are not hooked up or not working OR the 2 wire analog switch is not a limit switch and is just there in case I ever wanted analog gauges.

I could disconnect them and see what happens. No point paying for the analog switches if they aren’t used

If you’re going through sensors that often, make sure your wires aren’t getting pinched when your drives are fully lowered. That’s what happened on my old boat.

 

[pyro]

I was mistaken on the manual wiring diagram. Mine shows a trim limit switch going through the outdrive. It says trim switch is unused. So I don't understand their wiring diagram, and I question if it is correct.

I did update other thread. Digital sender only worked for me on my boat with DTS & smartcraft gauges.

My wires going through the transom assembly in the engine compartment were clearly labeled "Digital sender", "Analog Sender" and "Mercathode". See if yours is labeled and what it says.

 

[Espos4]

This boat doesn’t have an override and the trim never shuts off as long as you hold the button.

Same here. I have DTS and Smartcraft too. There is no separate “trailer” button and the button to raise the outdrive doesn’t have a second detent. It’s only “up” and “down”.

As far as I can tell, that’s just the way they made it.