Help With Fuel Guage Malfunction

[stal87]

I just picked up a 1986 Bayliner Capri 1650. Pretty decent shape except for the cracked upholstery. Maiden voyage yesterday turned up a non-working fuel guage. That is gonna bug the heck out of me.

Is this common for this boat? Do you think it's an easy fix? What are the first things to check? Maybe something as simple as a fuse, where is it? Do you suppose the guage in the dash just needs replaced? Hopefully the problem doesn't lie inside the tank!

Thank you all for your advice.

 

[NYBo]

Re: Help With Fuel Guage Malfunction

The first thing to check is the wiring: from the sending unit in the gauge, power leads to the gauge, and the grounding wire for the tank.

 

[Silvertip]

Re: Help With Fuel Guage Malfunction

There are well over fifty responses to this exact issue so use of the "Search" feature would have turned it up for you. There are four parts to the fuel gauge system. 1) the gauge, 2, the sender in the tank, 3) the wire between the sender and the "S" terminal on the gauge. 4) +12 volts and ground to the gauge when the key is on. To check the gauge, short the "S" terminal to the "G" (ground terminal). If the gauge is indeed properly grounded, the needle will peg FULL indicating the gauge is ok. If not, make sure you have +12 volts on the "I" (ignition) terminal on the gauge. Make sure the ground terminal is actually grounded. Try again. If still the needle doesn't peg, the gauge is bad. If ok, disconnect the send wire from the "S" terminal. Measure resistance of that wire to ground. If you know roughly how much fuel is in the tank, a full tank will read 33 ohms, 1/2 tank will read about 109 ohms and an empty tank will read about 240 ohms. All of these numbers are give or take a bit. If the sender measures wrong or no reading on the wire, move directly to the sender (at the fuel tank) and try the measurements again between the threaded terminal on the sender and the sender shell. If still wrong, the sender is bad.

Here is the diagram of the typical fuel gauge system (again).

 

[milmat1]

Re: Help With Fuel Guage Malfunction

Mine was the sending unit, (Usually is!) You can get a universal replacement from IBOATS store or ebay..Replacement is simple! If the wiring is all OK, You can check the sending unit with an ohm meter as described above...