Fuel Gauge

[TheDodgeMan69]

I have a 92 W350 that i bought almost 3 years ago and the fuel light would come on when the fuel gauge showed 1/8 of a tank left. I recently noticed the low fuel light comes on when the fuel gauge shows empty. I'm concerned about if the low fuel light first comes on, do i still have an 1/8 left of fuel in the tank seeing how the fuel gauge shows empty. Has anyone else had this problem?

 

[Bob Beauchaine]

In theory the low fuel light is supposed to come on when there is about 6 gallons left in the tank. I go more by miles traveled and under what conditions those miles were traveled. I would not count on the light as being all that accurate.



Bob

 

[cerberusiam]

At the point these trucks were new there is was supposed to be about 6 gals of fuel left when the light came on. As the sending unit ages or the float gets heavy the readings farther and farther off . Normally it errors on the high side and you have more fuel than shown but it is still invalid so don't trust it.



I have one that looks to be correct on the gauge and light but is erring on the high side, 8-9 gal of fuel left. Another one will hit empty and turn the light on with over 10 gals in the tank. A different that is effectively empty at 1/4 of a tank.

 

[TheDodgeMan69]

So I shouldn't worry about it? Should I replace the sending unit? I would hate to run out of fuel due to the gauge not reading right.

 

[cerberusiam]

You can replace the sending unit or fill it up at different gauge readings to see if it is off and consistently off. Just depends on how pressing the need for the reading to be as close as possible to correct.

 

[TheDodgeMan69]

Thanks I will try next time I fuel up.

 

[RedRamAndy]

I gave up on my low fuel light in my '89. I replaced the bulb when I had the dash apart and found out why the darn thing burnt out in the first place. It never goes out! The little circuit board in that warning light cluster looks like it has a few cooked components on it too. I doubt those are available.