2015 Four Winns fuel gauge

[newbie_nick]

Hello all... I am a new boat owner and new to the forum. Thank you, in advance, for your help!

I just purchased a 2015 Four Winns H190 RS, and the fuel gauge is not working. I have watched a few YouTube videos about diagnosing fuel gauge issues, but my gauge is a cluster with speedometer, voltmeter and fuel gauge together. This seems to complicate things a bit.

I think that I have figured out that the large black (shielded) cable is for the speedometer gauge, and the voltmeter and fuel gauge are in the harness. Based off of my research, I think that pink is fuel signal, purple is switched power, and yellow is ground. From the Four Winns electrical schematic, I think that blue is the cluster lighting.

What I've observed:
Speedometer works
Voltmeter works

Questions:
1) Does it seem like I have the wiring identified properly from the colors?
2) When I turn the key to the boat 'on', the voltmeter rises but the fuel gauge does not budge. I assume that the voltmeter is reading voltage from purple back to yellow. Does that seem correct?
3) Since the voltmeter is getting good ground, I assume that either the pink wire from the sending unit is bad, the ground from the sending unit to ground is bad, or the fuel gauge is bad. Does that seem to make sense?

My next moves:
1) Measure resistance between the pink wire and yellow wire at the harness.
2) Measure resistance between the fuel sender ground to a good ground (- terminal on the battery)

Am I thinking through this the right way? I would appreciate any corrections to my statements above or thoughts on diagnosing this.

Thank you!
Nick

 

[Fun Times]

Yes for the most part you're correct in your assortments of thoughts and wiring colors.

About the only 2 things I noticed not mentioned would be the possibility of having a fuel sending unit issue inside the fuel tank either it be electrical or mechanical... Or not testing the fuel gauge portion directly to know if it's actually gauge issue or other heading back to the tank as far as quick references goes.

To test the gauge, you ought to be able to ground out the pink wire with the key on say either at the fuel tank or jump gauge pin numbers 4 and 6 (Pink and Yellow) and see if the gauge maxes out such as you'll see in the following video just passed the 2 minute mark.

Have you tapped on the front of the gauge lightly to see if the needle is just stuck when power is on?

 

[Scott Danforth]

Most likely corrosion or bad connection at the tank sender. Check there. Check continuity of the pink wire

 

[newbie_nick]

Yes for the most part you're correct in your assortments of thoughts and wiring colors.

About the only 2 things I noticed not mentioned would be the possibility of having a fuel sending unit issue inside the fuel tank either it be electrical or mechanical... Or not testing the fuel gauge portion directly to know if it's actually gauge issue or other heading back to the tank as far as quick references goes.

To test the gauge, you ought to be able to ground out the pink wire with the key on say either at the fuel tank or jump gauge pin numbers 4 and 6 (Pink and Yellow) and see if the gauge maxes out such as you'll see in the following video just passed the 2 minute mark.

Have you tapped on the front of the gauge lightly to see if the needle is just stuck when power is on?

Thank you for the feedback!

I have watched that video before, and it was very helpful. I need to figure out a way to jumper the pink to yellow while the harness is plugged into the gauge. The video makes it seem so easy because there are exposed terminals to jumper across. The harness mechanism just protects everything, too well! I might trace both the pink and yellow back from the harness to see if there is access to both under the dash somewhere. If that is the case, I should be able to jumper them and look for the gauge to max out.

Your comment on the fuel sender unit is valid, too. To be honest, I thought that I had a fuel sender unit issue because it was not reading any resistance when I measured it directly. I thought that was the issue and replaced it already. The new fuel sending unit measures 33 to 240 ohms at the sending unit, but the gauge is still not working.