Finicky Fuel Gauge

Jns1981

Cadet
Joined
Jul 13, 2017
Messages
24
'87 Cobia 189 Monte Carlo... its a junker, but great fun on the Hudson!

The past two trips the fuel gauge has been odd... it randomly reads empty for a bit--then "wakes up" and reads accurately.

I'm new to anything electrical in regards to boats. Engine/mechanical things I can handle... also, its embarrassing-but I don't even know how to find the sending unit to check/problem solve.

Any advice on where to start would be amazing. I looked at the gauge behind the dash and its a plate of spaghetti!! The wiring is insane!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
51,243
clean your connections at the fuel sender and at the gauge.
 

legalfee

Chief Petty Officer
Joined
May 10, 2018
Messages
405
Usually the sending unit is inside the tank but the terminals are on the outside on the top. There is ground and sense wires. As Scott says clean the terminal connectors and put dielectric grease on them. The sender should read 33 ohms full and 240 ohms empty.
 

Jns1981

Cadet
Joined
Jul 13, 2017
Messages
24
checking the unit makes sense.. im baffled as to where it might be. Its a junker.. it has a board/floor over the old soft floor as a quick/dirty fix... i realize i need to remove the "2nd floor" but should the inspection port be easy to find? is it typically under the carpet?

its an 18ft bowrider with a ski locker.. assuming the port would be between the ski locker and the engine cover? correct?
 

Lightwin 3

Petty Officer 1st Class
Joined
May 18, 2010
Messages
300
checking the unit makes sense.. im baffled as to where it might be. Its a junker.. it has a board/floor over the old soft floor as a quick/dirty fix... i realize i need to remove the "2nd floor" but should the inspection port be easy to find? is it typically under the carpet?

its an 18ft bowrider with a ski locker.. assuming the port would be between the ski locker and the engine cover? correct?

Where is the tank? If it is in the floor, the sender will typically be near the rear of the tank.
 

Jns1981

Cadet
Joined
Jul 13, 2017
Messages
24
i believe the tank is in the floor. is there always a port for the sender unit?
 

legalfee

Chief Petty Officer
Joined
May 10, 2018
Messages
405
This is a typical fuel sending unit
 

Attachments

  • photo291839.jpg
    photo291839.jpg
    16 KB · Views: 0

Jns1981

Cadet
Joined
Jul 13, 2017
Messages
24
If an access cover isn't present, is the only other solution is to cut one in order to reach the sender unit?
 
Top