Mercruiser trim indication

[gary fluke]

I have a 1994 Mercruiser 4.3 liter Alpha One, Ser.#329256. I bought the boat earlier this year and the trim indicator has always shown the drive unit to be in the full up position. I found the trim sensor to be full of grease. After cleaning everything I checked the sensor wheel. With one ohmmeter probe on the contact strip and another on the resistive strip 180 degrees from that, a sweep of the resistive strip shows a range from continuity to virtual infinity like one would expect. I cleaned the wipers which sweep the strip, too. It still doesn't do anything but read full up. A jumper across the wipers causes the meter to read full down, which looks correct. So why doesn't this system work? Thanks for any ideas!

 

[Trent]

Re: Mercruiser trim indication

Turn the drive one way or another so that you can see. Merc wiring falls apart over time. Look inside the gimble for the wires from the sensor. Is the insolation on the wire falling apart? Very common and a pain to replace.

 

[gary fluke]

Re: Mercruiser trim indication

Thanks Trent, I will check that out. I have been thinking the wiring may be OK since the jumping of the wires causes the indicator to read full down.

 

[Trent]

Re: Mercruiser trim indication