99 mustang fuel gage stuck on half, low fuel light works

The low fuel sensor is a part that plugs onto the instrument cluster fuel gage circuit ribbon.

If it cranks good but won't start, have a helper crank it while you visually check for spark at the spark plugs. If spark everywhere, use a fuel pressure gage and check proper fuel pressure. If no schrader valve it makes it a little more difficult to check fuel pressure, meaning you'll have to tee into the supply line with gage and proper fittings. Some fords don't have a Schrader valve, but, it may have a fuel pressure pid so if you have the proper scanner you can read that pid.
Also, check for fuel injector pulse, engine cranking. Check for applicable trouble codes. To check codes, yourself, at the least, you need an obd2 code reader.

The most likely problem is the fuel level sending unit in the fuel tank. It is a rheostat that is hooked up to a float in the tank. When the tank is kept at 1/2 tank or less than the rheostat stays at that spot and makes a open in the circut. When the circut is open or the resistance is low the guage goes towards full. When she fills it up the float rises to a spot on the rheostat that is not warn yet and works. The fix is to replace the fuel level sending unit in the tank or use the trip odometer to log how far she has gone on a full tank.

The fuel gage shares the same fuse as all the gages, so if the fuel gage is inop and all other gages are working then you have another problem. The most common cause is that the sending unit for the fuel gage inside the fuel tank is defective, that is true 99% of the time in my 35 years of repair work.

the "sensor" is actually just a long arm with a "floaty? on the end and gauges where in the tank the top of the fuel is located therefore giving you a read out on your dash. the sensor your talking about sounds like the low level readout sensor.this is located elsewhere and is simply asensor that reads the information of of the fuel pump and vocalizes low fuel warning. if you knowingly have fuel in your vehicle then your sensor may be shorting or or your dash gause has a short.

try the multiplug connection on top of the tank

either the fuel sender in the gas tank is bad or the bcm is bad,most likely sender

I took the vehicle to the Jeep dealership, and the problem went away before they could check it out. They are going to check wiriing next, because the check engine light went out on its own, and the fuel gage began working corectly on its own. Not sure what caused it, but hope to have an answer from the dealer.

This is a common problem with Malibu's. It is due to cheap metal in the fuel gage that corrodes. Chevrolet knows about this but they refuse to issue a fix. The check engine light staying on and the faulty fuel gage are related. This is a defect and they need to recall this part! Raise hell with the dealership!

It could be the fuel level sending unit is stuck or going out. It's in the gas tank.