Fuel Gauge not synching

[Passin'Gas]

I have a Riviera with dual fuel tanks and a single gauge. There is a toggle switch that switches the gauge from the left and right tanks. My problem is that one side shows on the gauge but when toggled to the other the gauge needle goes below the gauge and does not register.

What do I need to do to synch the gauge to both tanks? I believe it's the sending unit. Does anyone know what type of unit I need?

[g36]

The problem could be with switch or at tank. HAve you checked the connectors at the sending unit on top of the tank for corrosion or if loose if so here's a link to check to save me typing it
http://www.boatingmag.com/checking-boat ... ding-units

[Passin'Gas]

Thanks. Great article! I'll do some checking this weekend....

[hausherrs]

I have these problems as well. I filled up Saturday because the gauges said I had 1/4 tank in each. But I was only able to get 40 in each (100 gallon tanks). And when I was filling up the stb tank I was about 1/8 from the full mark and fuel came out the breather. When I am holding down the toggle to check the levels the needle jumps around on its way up and will eventually settle where it thinks the fuel level is. Obviously wrong. Ill be down in the er today after work and I will check connections. But im betting that my senders are bad. They do both behave the same though, so maybe its the switch.

Steven

[mjk1040]

I'd lean toward the sending unit, but hey u never know with electronics. Mike
PS-Check the ground!

[RGrew176]

Could be a few things. I have the same set up. A switch that I mover from left to right to check the fuel levels in each tank. Earlier this season I lost the starboard tank. I moved the switch to the starboard tank and I got no reading. After reading other posts here and in other forums I pulled the starboard aft cabin bed so I could get to the tank. I checked the connections and they were tight. I then disconnected the wires and cleaned them and the connection on the tank. I also pulled and cleaned the ground. After reconnecting the wires the switch worked once again.

It could be something as simple as the connection, but it could also be the sending unit. Hope you figure it out.

[Passin'Gas]

Thanks guys. I think the obvious place to start is with the connections, wiring and ground. Let's hope it's that simple. Failing that, I'll check or replace the sending unit. If it's at all corroded it's likely not a bad idea to spend the $100 and get a new one (or two).

I'll keep the updates going....

[hausherrs]

Mine turned out to be the upper helm switch (Possibly the upper guages, I have not replaced anything yet). I have a lower also and I tried the switch there and I have one tank full and one tank 3/4, which explains the list. Replacing the switch today.

[mjk1040]

Hope that fixes it. Can you exchange the switches from the lower helm to the upper to be sure its the switch?

[hausherrs]

Qr Bbpost Hope that fixes it. Can you exchange the switches from the lower helm to the upper to be sure its the switch?

Ther appear to be the same switch. Ill give it a shot.