69 Low Fuel Light

[69z28302]

Just got around to adding fuel to my car before starting it. Installed new tank ect during restoration. Fuel gauge shows a half tank but the Low Fuel Light is stiil on. Any suggestions on what to start checking?

Thanks CRG

Mike

[GaryL]

Those repro light modules are not the best. They are known to be pretty inaccurate. But 1/2 tank off is a lot.

[69z28302]

Thanks Gary. The car has the original module and guage cluster. I didnt replace it.

Mike

[69pace]

I would check the ohms at the gauge and then at the low fuel module to make sure they are the same reading.

[69z28302]

OK ,I do it.

Mike

[69znut]

Resistor Values:
  0   ohms = MT tank.
45   ohms = Warning (general area of alarm with “GM original” Low Fuel Sensor).
90^ ohms = Full tank.

[69z28302]

Could a ground somewhere be my problem?


MIke

[69pace]

Mike - don't think so as I assume your gauge in the console is using the same ground as the low fuel monitor is.
But the low fuel monitor should be getting the same oms from the tank sender and report the same levels as the gauge.

That's why it is important to test the gauge, the tank sender, and the low fuel monitor. If you get 45ohms (1/2 a tank) at the sender, and the gauge and you test the monitor and get less then 45 the wiring or the monitor itself would be suspect.  Your base line test of the sender lead in the trunk will be the only standard, assuming you KNOW how much fuel is really in the tank.  

Here is a troubleshooting I wrote over on TC http://www.camaros.net/forums/showpost.php?p=1579191&postcount=2 see if that helps you run the tests.

[69z28302]

OK K will try to check this weekend. Thanks for the info

Mike