Trim Gauge Question

[Chris611]

I have a '96 Mercruiser Alpha I drive unit. My boat has Faria gauges. The trim gauge seem to read alright for the most part. When the unit is "trailer" trimmed, the gauge reads all the way up. When I lower the trim in the water though the gauge reads just below the halfway point. The needle never reaches the bottom of the gauge. I wish it did so I had more resolution. Now my entire operating trim range is from 2:30 - 3:30 positions on a clock. With Trailer Trim being at 1:00. The gauge reads full down at 5:00. Any thoughts on this? <br /><br />Thanks<br />Chris

 

[Bayrider]

Re: Trim Gauge Question

Hi Chris. <br /> You need to re-adjust the Trim position sender on the starboard side of the Alpha drive.Go to this site www.mercstuff.com/trim_limit.htm

 

[Chris611]

Re: Trim Gauge Question

Thanks Bayrider. I adjusted it and now the needle moves down farther. <br /><br />I also noticed that it seems that the needle sometimes comes to a stop and then will start moving again. I put the tongue of the trailer on the ground so I could get the lower unit high enough to trim it all the way down or in. I hooked a volt meter up to the return voltage prong of the gauge and it looks like there are times when the lower unit is moving, but the voltage isn't changing. Does that suggest that the sending unit is bad? Can it be replaced without changing the trim limit switch? Can I service the sending unit? Any thoughts.<br /><br />Thanks<br />Chris

 

[rickdb1boat]

Re: Trim Gauge Question

You can take the wires off the sending unit and useing an Ohmmeter connected to the sender wires, move the sender up and down and see if the resistence changes smoothly. If so, it should be good.. I believe it should go from 1-88 Ohms if working correctly..

 

[Chris611]

Re: Trim Gauge Question

Thanks Rick. I took the sending unit apart and it appears that the 4 o the 6 plastic prongs are broken off the sensor. So I don't think the prongs are properly engaing 12pt female star "thing" that drives the sensor. I assume I can't just buy that part. Think any boat shops would have some old sensors that they have junked and I could buy that part? It also appears that a 1/4" bolt head will fit into the "thing". I wonder if I can find a nylon nut and expoy it onto the surface with the broken prongs? <br /><br />Chris