twin 150 hpdi fuel management

[CaptFreddy]

I have a set of 02 hpdi 150' . When I bought the boat the fuel management gauge was sun faded and unreadable so I replaced with a new gauge. Every so often the port engine would get a reading but not stbd so I replaced both sending units. Now nothing! So where do I go now? Wiring harness or is there a setting on the back of the gauge (the switches)? Any help is appreciated thanks

[Hollywoodfish]

I had the same exact issue with the same setup. I replaced the senders and the gauge. It wasn't until I replaced the wire harness it fixed the issue. Did you make sure that the gauge settings were set to the gauge that you removed? (calibration settings) You have to remove the rubber grommet and move the little switches around. My guess would be the wiring harness, you know what saltwater does to wiring on a boat!

When you say nothing? are you even getting power to the gauge?

[CaptFreddy]

Yes have power just no readings from sending units. Considering it's age and the fact I plan on keeping the boat for a good while I'm going to go ahead and replace the harness anyway and hopefully that's it. As far as the switches on the back I was unaware of them at the time of installation and can't find the old gauge. Anyone know the pattern for twins

[Hollywoodfish]

There is no set "pattern" for the switches to be set. You would have to fill the tank with gas, run all day, check your fuel burn, and refill with gas again. If the numbers are off then you need to calibrate the gauge with the switches. there should be a card that came with the new gauge. It shows what switches to move based on how off your burn was.