225 Optimax digital trim SN 1B389342

[MattVT18]

I mentioned in another post about my trim acting funny during my break in. The analog trim gauge was pegged full up and wouldn't move. I poked around and found that there wasn't a trim sensor installed. I picked up a digital trim sender (859187A1) to use with my MercMonitor gauge. Got sensor installed and turned key on. I got a trim reading right away that changed as I trimmed the motor up and down. I went through the calibration and now the only readings I get are 25 while full down and 0 when moved anywhere else. I cycled the key two or three times with no change. I removed the sensor and used a screwdriver to rotate the device with the same results, either 25 or 0. The trilobe pin is installed. While I had the sensor off I trimmed the engine up/down and noticed very little movement of the slotted part where the sensor engages but there is movement. Any idea what would cause it to apprear to work prior to calibration then not work? I haven't started the engine since the calibration but the manual seems to indicate key on/off is all that's required.

[EuropeanAM]

Improper calibration, more than likely.

Go into the calibration on your Smartcraft Instrument. There are 3 Steps:

-Trim engine DOWN as far as it will go (DOWN POSITION). SAVE.

-Trim engine up to the end of the short trim rams (just before "fast" operation starts), (MAX TRIM position). SAVE.

-Tilt engine up as high as it can be raised safely without contacting anything (TRAILER position). SAVE.

Complete the steps to exit the calibration, and the see if the trim works properly.

Note: On units that give you an option to use HIGH RES(olution) TRIM: Choose YES.

Be careful with the trim sensor- it has limits in how far it can be rotated without potentially damaging it.

[MattVT18]

Improper calibration, more than likely.

Go into the calibration on your Smartcraft Instrument. There are 3 Steps:

-Trim engine DOWN as far as it will go (DOWN POSITION). SAVE.

-Trim engine up to the end of the short trim rams (just before "fast" operation starts), (MAX TRIM position). SAVE.

-Tilt engine up as high as it can be raised safely without contacting anything (TRAILER position). SAVE.

Complete the steps to exit the calibration, and the see if the trim works properly.

Note: On units that give you an option to use HIGH RES(olution) TRIM: Choose YES.

Be careful with the trim sensor- it has limits in how far it can be rotated without potentially damaging it.

I did exactly what you posted, multiple times actually, each with the same result. It's strange that it seemed to work right away then stopped after the calibration. I have high resolution turned on but did change the pop-up time from 3 sec to 1 sec. I'm hoping it didn't get damaged while calibrating it. When I used the screwdriver I only rotated it about an eighth of a turn and if felt very free. I'm going to look at it some more tomorrow. Probably disconnect the three wires and see if the engine side needs to be cleaned up any. The connectors looked fine and everything plugged in tightly but I guess some thing could have happened while moving everything around. The service manual for my last engine lays out how to test the sensor with a multimeter so I'll probably see what that shows me well. I will say that while I was working on it today it was very cold (mid-upper 20s) and the MercMonitor was pretty slow to respond to button pushes. I wasn't on the water, just under my carport and since it was so cold I didn't hook up the hose to run the engine. The voltage on the monitor showed 12VDC, but like I said it was very slow to respond. Its supposed to be warmer tomorrow, so I might take it to the lake and let it run some and mess around some more.

[MattVT18]

Update from this morning:

On further inspection the tri-lobe pin was not fully seated. I was able to pull it out with pliers. I checked it over and re-installed it using a hammer. It drove in fully and seemed tight.
Checked sensor sweep from lock to lock and moved smoothly.
Verified operation of slotted rod end as someone trimmed engine up/down. Seemed smooth. Lots more rotation after getting into the tilt section but I guess that is to be expected.
Measured voltage between black/orange wire and yellow wire per service manual. This is where it got weird...at the "trailer" position (full up) I was reading about .1 VDC. As engine was trimmed down the voltage smoothly increased up to about .6 VDC then all at once jumped to ~ 4.5 VDC just before full down. This doesn't seem to agree with the manual at all, it's actually opposite. It's also a little concerning that the voltage makes a large jump seemingly all at once.

Not really sure what to make of it at this point. The sensor was new in a sealed bag when I bought it. It gave readings that changed right away after installing but has not worked right since the initial calibration. Kinda sucks if it's bad as I probably can't return it, I'll just have to eat it. Maybe the shop will have some pity on me since I've done business there before (they have a sign about not returning electrical/electronic items once installed). I'm heading to the lake a little later and will try a calibration with while on the water but am not expecting any change.

[JOE54]

one year warranty on defective parts .

[MattVT18]

JOE54 - I agree but it might be hard for me to prove I didn't damage it on install if it's actually bad.

[EuropeanAM]

Wondering if the tang was rotated past the max range (thus putting the sensor's variable resistor "pot" switch out of range).

There is a mark on the back side of the sensor, and the tang, that are supposed to align (they're aligned when sensor is removed from the bag), and this position correlates to (approximately) full UP trailer position.

[MattVT18]

I'll check that out tomorrow Don. I tried to find some technical info on the sensor to see how it worked but came up empty. What you said makes sense, it seems like it's "counting" the wrong way.

[JOE54]

[MattVT18]

Don - do you have a pic of the orientation out of the bag? I don't see any obvious markings on the sensor. At full up, there is only one way everything will fit together. I pulled the tang out of the body, it will fit back in different than removed and still allow full travel. I've tried every combination I can make fit and still allow full rotation with the same results. I can set the sensor to read 25 (full up) but there isn't any way it'll mount (the tang is almost 90 to the body of the sensor) and the engine still has too far to travel to make up. My rigging tube is pressing pretty hard against the transom but it need way more travel. I can pull the tang out and rotate it to the point it goes back together (now it's nearly parallel with the long side of the body) but I have to trim the engine down to the point that I couldn't even get the transom saver on to get it to mount.

[EuropeanAM]

If you were to treat it like the face of a clock (with screw holes at 6 and 12), the tank usually faces (approximately) 5 and 11.