Trim Gauge

[Eric Allred]

I have a Mercurser 5.7L outdrive, the trim gauge stopped working. I measured the voltage at the gauge, with the engine running I get ~13 volts on one side and 9 on the other pole with the drive approximately half way down in neutral. The gauge reads all the way up. Is the issue the gauge or sending units?

 

[Loyd Dinneen]

Your trim pucks on the oudrive have gone bad or the wiring is rotted thru. It gets all crumbly and shorts out where it comes thru the transom. You will have to replace it by possiably removing the outdrive and rerunning it thru the transom. The procedure is on the web. Have fun.

 

[skibum]

Mine haven't worked in 3 years. I gave up on replacing the pucks every couple of years. Besides the annoying "Fault Trim" message that I have to clear a couple of times a day, I found that I really don't need it. I've gotten used to trimming it by feel and the look of the prop wash.

 

[Pirate Lady]

What they said. Boat was recently out of water. Mechanic said need pull out drive off, will wait til winter when we do gimbel, bellows inspection. Then again in 2 years when it quits again. Cause 2 years is about all you get.

 

[Bt Doctur]

With slight modification of the wiring you can have it last a lot longer. The wire fails because its not rated for underwater use and has constant voltage applied to it when the key is in the "on" position.
Using 2 diodes to have power to the gauge ONLY when you press the trim button for the gauge to respond.

Remove the 12v feed to the gauge, install a new wire to go to the control box and locate the trim wiring.
Carefully split the wiring and skin DO NOT CUT ANY WIRES the Blue and Green wires about 3/8ths. Connect a 1N34 diode to the Blue a wire and one to the Green wire.
connect the other ends together and to the new wire from the gauge.Polarity is important with diodes. They are 1 way valves so to speak, power from the wire thru the diode to the gauge when you press a trim button.

THe band faces the gauge wire

 

[scoflaw]

That untinned wire is a joke, looks like Walmart lamp cord.

 

[Bt Doctur]

click to enlarge