Where is my trim sending unit wire???

[ScurveeDog42]

I have a 2001 Crest Pontoon boat with a 2001 90HP Johnson (J90PLSIF) with a console cutout for a trim gauge.( I really need the gauge - can't see the motor
when driving). I have found the black/purple/and blue pigtails behind the panel.
I can not find a white/brown wire to save my life (which is the sender, I think).
I am 99.99% sure I have a sending unit. I will try to attach a photo to show what I think is the sending unit. The other photo is of a long wire that comes up
in the engine compartment and is very long. One end goes to a connector,
and the other disappears up under the engine and I lose track. I suspect that
there is wire -maybe this long wire- that runs from the sender to a "buss bar"
inside the motor. What is missing is the wire from the buss bar, out of the motor
compartment to the instrument panel (as a brown and white wire). If I am right,
I don't think I am inclined to take the motor apart to hook up this wire, although
for some of you folks this would be a walk in the park. I can't kill my motor, or my kids would kill me. :^) Comments welcome.

 

[rickdb1boat]

Re: Where is my trim sending unit wire???

That is indeed the sender in your picture. I can't say what the wire is in the other picture. All you need to do is figure a way to get one wire from the sending unit up to the dash. You will have 2 wires from the sending unit. One will go to ground (normally right by the sender) and the other goes to the gauge.

 

[ScurveeDog42]

Re: Where is my trim sending unit wire???

Thanks for the reply, Rick!

 

[jhebert]

Re: Where is my trim sending unit wire???

In some OMC installations there is an isolated ground lead for the TRIM gauge which is carried on a wire with insulation coded BLACK with WHITE STRIPE.

The wiring of the TRIM gauge is shown in a schematic and the circuit operation explained in accompanying narrative in an article at

http://continuouswave.com/ubb/Forum6/HTML/002089.html

 

[ScurveeDog42]

Re: Where is my trim sending unit wire???

Well, I just came back in from a successful mission, thanks to Rick's advice, and
I pulled the sender off and found my elusive white/brown wire. The trouble was,
there was also a black wire. This made sense, but I hadn't thought about running two wires. I ran one to my new gauge and it works great. But, now, having read these other comments, I am concerned that this might be an isolated, or paired, ground. That would make sense, too. But, it worked for
now. I am wondering if I will have problems when I turn on the panel lights. But, at this time, I won't worry about it. It is nice to have a trim gauge. This forum is a great resource.