Fuel gauge started giving bad readings

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Hi all, I have a 2003 Bayliner 185 with 4.3L carb Mercruiser and Alpha 1 Gen 2 that I have owned for 4 years. The boat has been very reliable.
The fuel gauge has always seemed decent.
This season I had two incidents. Scenario #1: the gauge read a little below 1/2 and the engine began to sputter. I imagine it was picking up air intermittently. Made it back to the dock, fueled up and everything was great.
Scenario #2: gauge was a little above 1/2 and it ran out completely. The readings seem to be getting worse.
Boat was loaded exactly the same. Same people, same gear.
Gauges are Faria.
Any ideas? Gauge, sending unit?
Thanks,
Joe
 
Last edited:

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Check for a solid 12V at the purple wire on the gauge. See if it increases to 14V with the motor running.

Next ground the sender terminal on back of gauge at it should peg Full

Next pull the sender, cover the hole then reattach wires to sender. Make a good ground connection from the tank to the sender. Turn key ON and raise and lower the sender watching the gauge.

If it does not work, peg sender lead to ground to cause gauge to peg Full

If it appears to be the send, use an ohm meter and measure the resistance with no wires attached. 240 Full and 33 Empty

Edit this is backwards: 33 Full and 240 Empty
 
Last edited:

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Check for a solid 12V at the purple wire on the gauge. See if it increases to 14V with the motor running.

Next ground the sender terminal on back of gauge at it should peg Full

Next pull the sender, cover the hole then reattach wires to sender. Make a good ground connection from the tank to the sender. Turn key ON and raise and lower the sender watching the gauge.

If it does not work, peg sender lead to ground to cause gauge to peg Full

If it appears to be the send, use an ohm meter and measure the resistance with no wires attached. 240 Full and 33 Empty

Wow! Great troubleshooting instructions! And the readings for resistance! That's awesome.
Guess what I'll be doing this weekend!
 
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