how does the trim sender work?

lime4x4

Lieutenant Junior Grade
Joined
Apr 25, 2007
Messages
1,040
I have a 86 mercruiser sterndrive. All the wiring for the trim sender is intact but the trim indicator doesn't always work. Sometimes it moves a little then pegs.I looked at the back of the gauge and it looks like it get's it's signal from 1 purple/white wire. I assume it uses voltage if so where would i find the specs to test the gauge?
 

BAYLINER185

Chief Petty Officer
Joined
Jul 30, 2007
Messages
474
Re: how does the trim sender work?

The trim sender is on the starboard side of the stern drive mounted right on the gymbal ring hinge pin.


What your gauge is doing sounds like the sender is not set properly. If one was to remove the sender completly and move it by hand this very thing would happen. The gauge moves from full up to down with the slightest amount of the sender turning.

What you need to do is lower your drive till the trim pump makes that funny noise when it reaches the full down position. Set the trim sender so that the gauge just starts to read full down position. Put it back on the gymbal ring if you did remove it completly to set it or if you just loosened the two set screws turn the entire sender until the gauge reads full down. Tighten the screws and raise the drive. Watch the gauge and see what it does.

IF you pulled the sender off the gymbal ring and are able to watch the gauge as you turn the sender SLOWLY and the gauge jumps all over the place then its problably shot. If you turn it too fast it will just peg one side to the other you need to do it really slow and if you can "Control" the pointer on your gauge then the sender is working properly.

I just replaced the sender and limit switch on my drive while the entire transom plate was off the boat for a major servcing. You can do it with everything installed it just depends on how much room you have to work with that will make it easy or really hard. You have to replace both the sender and limit switch. You will need the manual to know what the full TRIMED UP ( not trailer ) measurment / posiiton is ( 22" for a BRAVO I )

Hope this helps determine your status.
 
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