Chrysler Repair: low fuel light on off on off: 2000 LHS, fuel level sensor, side kick panel

Question
2000 LHS the low fuel light comes on and off all the time.and makes the tone it doesnt matter if the tank is full or mt it just keeps coming on and off please help me.. thanks

Answer
Hi Jerry,
That is an unusual problem. I am limited in that I don't have any wiring diagrams post '97, but I checked into the design of the fuel level sensor up to that time and can tell you the principles as to how the warning light works.
The tank has one sensor of the fuel level, a variable resistor attached to a float (this is conventional). The voltage from the resistor is received at the body computer under the dash where its reading is digitized and sent as a signal on a twisted-pair of data bus wires to the instrument panel in a stream of data that includes many other digitized signals needed to run the cluster.
If the fuel level is not jumping up and down on the gauge that might suggest that the sensor in the tank is o.k. and the problem is in the way the voltage signal is being handled by the body computer. It is possible though that the time constant of the gauge is such that it would not display intermittant changes in the voltage due to a faulty sensor in the tank (the jumpy signal being smoothed out) while the low level warning light could have a short time constant that would notice a faulty sensor in the tank. My inclination would be to measure the voltage from the sensor at the body computer (under the dash on the passenger side kick panel:the dark blue wire at pin 23 of the 25-pin gray colored plug). If the voltmeter remains steady while you are driving then you have to blame it on the body computer, if it is jumping around then a new float unit and variable resistor would be needed in the tank.
It is a hassle and unfortunately there is no easy way to turn off the tone unless you just want to eliminate all the tone warnings for various other hazards (the speaker for the tones is also on the body computer so you could cover that up). But before doing anything about the problem I would do that voltmeter reading so you don't spend money one way or the other without knowing for sure which part of the system needs to be changed.
As a caveat, recall that I don't have the 2000 year wiring diagrams and I am assuming there was no revision in the interim.
Roland