erratic fuel gauge

Quint4

Quint4

Well-Known Member
TECHNICAL Contributor
Oct 6, 2006
6,750
NC
Boat Info
CY 3375
Engines
7.4 MPI twin
My fuel gauge indicator jumps all over constantly. I am hoping it is not the sending unit in the tank because there is no access ( I will have to cut a hole in the cockpit floor to remove it ). Has anyone had a similar situation ?.I am going to remove the gauge and inspect it tomorrow.
 
How did you do with this? Are you sure there isn't some corrosion or a loose wire causing the gauge to jump? I hate to post such a stupid question but thought I would ask...

Dan
 
There should be access for the fuel lines and sending unit on the tank. It has to be there. Put a meter on the remove the wire on the sender and remove the wire behind the gauge and measure the resistance with a decent multimeter. If it's erratic at the sender, replace the sender. It it's OK on the wire at the gauge, replace the gauge. Otherwise it's wiring.

Best regards,
Frank
 
There is "access" as I have about 4" between the tank and cockpit floor. If I need to remove the sending unit it looks like I will have to cut a hole above it ? The connections to the top of the sending unit look good ( one connection is covered with silicone ). Frank I think I understand your troubleshooting...check for resistance or lack of continuity of wires between gauge and sender...I will try that, Thanks.
 
Quint

I had to replace the sending unit on my 94 290. I guess I was lucky in that my sending unit was far enough back I could lift it straight out. Use a jumper wire to cross the contacts on top of the sending unit and if the fuel gauge pegs to "full" you have a bad sending unit. I forget if you need the key on or off for this test.

Jeff
 
Well I ordered a new sending unit and after 2 grueling hours I got it in the tank...problem fixed ! I had to bend it very slightly to get it in, but it appears to work fine. I also had to stop at one point and bandage my bleeding arm...wrestled with sender blindly between top of tank and cockpit floor...a few choice words were uttered.
 
I own a 2006 Sundacer...the fuel gauges stay at full for along while and then dance all over the scale...is there a known issue with the units or gauges in the 320?
 
I have a 1991 290 Sundancer and the fuel gauge just stopped working. It just sits on "E". I jumped the wires together and the needle jumped to full. This means I have a bad sending unit... Correct? I have the same problem as Quint4. There is no access. There is an access but it is over the fuel line, so I could barely even get to the wires to jump them much less remove the sender unit. Quint4 how did you do it?
 
Not sure if this is relavent but on my 89 300, there are small storage compartments in the cockpit on both sides of the boat. Removing the false back to these revealed access to my senders, although you have to be a bit double jointed to get in there (lol). Does your boat have anything similar?
 
I wish! The sending unit is right in the middle of the tank and the only way to get to it is to stand in the engine compartment and squeeze your hand in between the top of the tank and the deck (about 3 inches of room).
 
As I said, it was almost impossible to do. I mangled the old sender to get it out. I worked a long time to get the new one back in and even bent it slightly to get it done. It has been working great since '08. I would look into different style sender or put in a deck plate above it....good luck. I also had a box fan rigged up about 10 ft away to keep the air circulating and disperse the gas vapors.
 
I would go with Jimmy's suggestion.
 
Yup I just found my next sending unit. My gage bounces like it has a short, it does give me a reading but you can hear it clicking.
 
Quint4. How many gallons is your tank? My tank is 100 but today I did the measurement on the outside of the tank for the new sending unit and I come up with 135 gallons. I am thinking that the part of the tank I cannot see is not shaped the way I think.
 
I orrdered it from West Marine but like I said I would look at installing the unit Jimmy installed if I did it again.

Item
Manuf.#
WM
Model #
Status
Unit
Price
QTY
Extended
Price
Electric Fuel Gauge Sending Unit, 6" to 24"
blank.gif
blank.gif

MOELLER 035729-10
8978314
YES
$39.99 USD
1
$39.99 USD
Cart Subtotal:
$39.99 USD
Tax:
$2.93 USD
Shipping:
$6.95 USD
Total:
$49.87 USD
 
You must log in or register to reply here.

Forum statistics

Threads
113,193
Messages
1,428,278
Members
61,104
Latest member
Three Amigos
Back
Top