Need Part#'s to add trim gauge

Hey folks, I've read a few post only to be worse off then when I started. I have a 2006 Yamaha F90TLR with 704 controls. I guess its 06 it was manufactured on 06/06. I want to add a trim gauge on. Here are my ?'s

1. Where on the engine in sending unit and harness hookup? (I'd like to see if I already have the harness installed or not)
2. Whats it look like? Square? How many wires? What colors are the wires?
3. Which Wire Harness part# do I need? Its going on a 20' pontoon.
4. Which Trim Gauge? I keep reading about 2/3/4 wire gauges and how 1 doesn't work with diff model years.

Everyone seems to be saying to just get the digital multi gauge, but that gauge is $300 on a good day. I already have a tach any other advantage to help convence the misses?

[dorf]

In the for what it is worth, category..

I've got a (factory installed) one on a 50 TLR, on a 19' Pontoon boat.

I'm not impressed with the analog trim gage.

It does not represent the actual movement of the engine. Ir just simulates it, (sort of). .....It does not indicate correctly and accurately through-out the complete range of movement--full up and full down.

Your tach (and ears) are the better way to determine engine/boat performance.

Again....just my opinion. ..I would leave well enough alone.

[boats.net]

You can get the multifunction tach kit 6YR-W0035-E2-00 which has the digital tach and also displays trim gauge, overheat and low oil pressure warning and has a hour meter. The kit includes wire harness needed to install. This may be cheapest way to go.
The analog trim gauge(6Y5-83670-12-00 or one of the 6Y7-83670) is set up to work with the analog tach(6Y5-83540-20-00 or one of 6Y7-83540). The wire harness 6Y5-83653-10-00 trim/oil harness connects to tach and trim gauge connects to tach.
If you are installing analog trim gauge without tach you would need to order
6Y5-83653-10-00 trim/oil harness(cut pink wire from 4 prong connector at gauge end and wire pink wire to pink sender lead on trim gauge) and connect to 4 prong connector on engine.
Also order 6Y5-83553-N0-00 gauge harness and connect to red,yellow, green and black wires on key switch. Connect other end to trim gauge.

Just so I'm clear if I already have an analog tach the harness will be already have been ran from the motor and attached to the tach. I just need to wire in the gauge jumping off the pink wire on it + others from starter switch.

Thanks to all you guys for your expert help.

[boats.net]

Yes if you have a Yamaha tach that has overheat and oil warning indicators in it then the wire harness will be there.