Fuel sending units

[1992330aftcabin]

Hello, I have a 1992 330 aft cabin. I just purchased the boat and now I’m trying to work out the bugs, after filling the fuel tanks gages only read half tank on both tanks, I was wanting to check the sending units. Has anyone had the sending units out and what is the easiest way to get to them.

Thanks Mike

[RGrew176]

Someone will be able to answer your question. Just hang in there. Fortunately on my 3007 aft cabin they are easy to access should the need arise.

[bud37]

Try a quick google search for how to check marine gauges and level senders, there is a ton of info on that with easy to do checks. The first one though is to make sure the tanks are full in the first place.....it is easy to miss that as some boats are a bit finicky to get right full.

[1992330aftcabin]

Thanks Bud, we made sure tanks were full. I think the previous owner ran ethanol blend fuel and may have damaged the float,but won’t know for sure till I can check the sending unit.

[Viper]

Let us know when you find how to access the senders, then we can post some diagnostic procedures. Can you not see then in the engine compartment? You can do one test without removing the sender but eventually you'll have to remove them anyway to test further. Make sure you have good clean connections at the sender and gauge first.

[km1125]

QR_BBPOST.... after filling the fuel tanks gages only read half tank on both tanks....

Do you have separate gauges or one gauge with a switch? If it's one gauge, I'd check the gauge before I started digging into the senders.

[1992330aftcabin]

KM1125, I have duel gages no switch. I find it funny both gages won’t go above 1/2 when tanks are full.

[bud37]

QR_BBPOST KM1125, I have duel gages no switch. I find it funny both gages won’t go above 1/2 when tanks are full.

That is interesting....can you tell if the gauges are the originals or been changed out.....maybe they don't match the rest of the dash...???

[1992330aftcabin]

Bud, all original gages.

[Midnightsun]

On the back of the gauge there is a connector/screw marked "S". This is the one that goes to the sender. Short it out to ground and see what the gauge does.

Now I do not know what it will do as they sometimes work backwards depending on which one you have but my guess is it will go to full which will confirm a sensor problem or bad connection most likely at the sensor. If it pegs to empty, simply remove the sensor wire and it should peg to full. The ignition does need to be on during your test by the way. If they peg to 1/2 it is the gauges or the supply of 12v to them is low.