Gauges don't work

Just bought the 2005 G3 boat (19') with 150hp Yamaha. Motor and boat come from Yamaha as a package. Neither the tilt gauge nor the volt gauge seem to work. Where to start with diagnosing? My first step will be to take the screws out of the instrument panel and lift out the entire panel for access to the back of gauges, and check wiring. Are the gauges fused? Does anyone have a wiring diagram. Call Yamaha? What could be the problem?

I'm not an expert on the electrical stuff, but there should be a fuse panel somewhere. Also, the gauges are all chained together with jumper wires. The jumpers are the power supply to the gauges. So those would be good things to check, fuses and good connections on the power wires.

there should be a purple colored wire running to those gauges that supply power from the ignition switch normally. I'm assuming yamaha follows marine wiring color schemes.
So if you pull the panel, check for voltage at that wire when turning the ignition switch on. If no power, then work backwards.

This doesn't answer your question but did you just buy the boat from a dealer or private party?

check the grounds to the gauges. normally the grounds are daisy chained to the ground buss

check the power to the gauges. normally the power is daisy changed to each gauge and runs to the ignition switch.

the yamaha factory service manual will have the schematic for the engine, controls and gauges (not the boat)

As highlighted, these are daisy chained together and thus if other gauges are working, then is probably not a fuse issue. Example: does the Oil Pressure gauge work? If yes, there is power and ground to that daisy chain. While it may be a the daisy chain connection to these particular gauges being bad, I suggest it’s better to crawl under the dash (if the wiring is accessible that way). Pulling out the panel can lead to more issues as the wiring generally does not have ‘excess’ to pull out and due to the probable crimp spade connectors used, you may disconnect some of them by accident.

If you do not already have it, you need a Multimeter (MM) along with some alligator type leads. These leads allow you to clamp onto a connection and not have to hold the probe there. Very useful. Here are a couple of suggestions link and link.

With these you can check both the Pos and Neg “power” for the gauges > if you need assistance with “how to” please ask.

Also, I suspect that your tilt and voltmeter gauges are not working for different reasons. But first check they are powered properly and let us know.

ESGWheel said:

As highlighted, these are daisy chained together and thus if other gauges are working, then is probably not a fuse issue.

Click to expand...

It can still be a fuse. A lot of them I've seen, the power is chained to the fuses, then from fuses to gauge.



This sad diagram shows what I mean. I usually see this kind of thing on older boats, where the dash has a panel with those glass tube fuses. Sometimes its own panel, sometimes with the gauge it powers. So a blown fuse won't kill power to the rest of the cluster.

This diagram really should be in crayon.

“Sad diagrams” still carry the point, so all is good, thanks for the info. While I am not familiar with the older boat designs, current boats (I assume) follow the protocol of the fuses protecting the wiring and not the device. For example, my 2005 Larson does not have fuses for each gauge. The “why” the wiring vs the device is best explained by Nigel Calder in this short vid link.

Regardless of which way this is wired having the MM with the clamp on leads will help the OP determine the issue.