innacurate fuel gauge

[gwman]

My fuel gauge reads 1/4 less than is actually in the tank (shows 3/4 when its full). It was installed new this year. Is there an adjustment I can do? Its in the water and I really dont want to bring it back to the mechanic - it'll take a week for him to return my call, one week for an appointment, and another before it finally is ready to take home. <br />How do I fix the adjustment?<br />Thank you

 

[andrewkafp]

Re: innacurate fuel gauge

Gwman<br /><br />Most boat fuel gauges (on the tank) I've seen are quite mechanical.<br />Just a spiral wound rod with a float that turns the rod as if elevates... thus moving a dial.<br />A car gauge has an electronic/mechanical device similar to a slot car contoller that sends a signal to the dial.<br />To adjust the resistor type.. you need to bend the float rod until it is accurate.

 

[sparkroost]

Re: innacurate fuel gauge

There is a potentiometer in your tank attached to the rod with the float on it. A potentiometer is a variable resister. the range of your pot is somewhere between 33-240 ohms. When the float is on the bottom it will be at one end of the scale, 240 ohms and 33 ohms when full. In order to check this out you will need to fill up the tank and REMOVE the 2 wires coming from the tank and put a meter on the sending unit(where you removed the wires). If you read 33 ohms the sending unit is good and the problem lies in the gauge or the wires that attach to it. I had the same problem and it was my gauge.

 

[gwman]

Re: innacurate fuel gauge

sparkroost - thats the kind of help i come to this site for - direct and clear. as soon as the weather around here clears up (rain rain rain rain fog rain rain fog fog rain) I'm going to do what you say. <br />thanks very much

 

[moderator1]

Re: innacurate fuel gauge

Moving to Boats.