My fuel guage is not working and always tells me i have a full tank. Will my fuel light still come on if my tank is close to empty?

I have a vauxhall corsa 1.4 sxi and my fuel guage says i have 349 miles left to drive, it has been stuck like this for weeks. When i have 10/20 miles left to drive will me fuel light still warn me? Thanks in advance
Experienced mechanics share their insights in answering this question :
This is a problem likely related to your fuel tank sending unit. The fuel tank sending unit is a small float type component (or sensor) inside your fuel tank that measures the level of the fuel inside the tank. As the fuel level drops, this change is detected and relayed in the form of a signal to the car’s computer which then displays the reading on the fuel gauge in your dash. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your fuel sending unit.

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If the fuel gauge reads full at all times, the probable causes are: The wire between the sender and gauge is broken and/or the connections are not good. The resistance wire in the sender is broken. The sender is not grounded and/or the tank is not grounded to the chassis.
1 Answer. The light flashes when you are going low on fuel (1 gallon left IIRC), and a solid light means get fuel now (1/2 gallon left). Now, if you have a full tank (i.e. > 1 gallon), and it is still flashing, the problem is most likely a stuck tank level float.
This issue is usually caused by one of a few issues – either the float has separated from the metal arm and isn`t sending any information about fuel level, the variable resistor is faulty and malfunctioning, or the wires in the system have corroded and are no longer sending information.
The low fuel light is incorporated into the gas gauge cluster and I will only speculate that if the gauge is not working then most likely the low fuel light will not come on. The light usually comes on when you have less than 3 gallons left for use in the tank.
Press and hold the “Trip/Odo” button and turn the car back on. While you`re holding the button, turn the key back to the “ON” position. Hold the button down for another 2 seconds after the car`s back on, then release.
The most common cause of an inaccurate or non-functioning gas gauge is a component called the sending unit. When you`re driving, the sending unit rubs against a variable resistor. This can lead to wear over the life of your vehicle.
They found that once the warning light comes on, there is usually about 10 litres (2.6 U.S. gallons) of fuel left in the tank.
They`ll charge you anywhere from $200 to $300 for the labor, assuming you bring the replacement gauge in on your own. The shop can get the gauge for you, but that will increase the total cost by anywhere from $300 to $1,000. Such damage may be covered by your car`s warranty, so be sure to check.
A fuel level sensor (FLS) is used in all automobiles to indicate fuel level. Various methods are used to measure fuel level such as resistive film, discrete resistors, capacitive, and ultrasonic. Resistive-based sensors are most commonly used for this application.
In a fuel tank, as the fuel level rises, the fuel sending unit float rises, and a variable resistor changes the resistance in the electrical current running to the gauge so it reads full. Depending on the amount of electrical resistance, the gauge will rise or fall according to the signal.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My fuel guage is not working and always tells me i have a full tank. Will my fuel light still come on if my tank is close to empty?
ANSWER : This is a problem likely related to your fuel tank sending unit. The fuel tank sending unit is a small float type component (or sensor) inside your fuel tank that measures the level of the fuel inside the tank. As the fuel level drops, this change is detected and relayed in the form of a signal to the car’s computer which then displays the reading on the fuel gauge in your dash. I would recommend having an expert from YourMechanic come to your location to diagnose and repair your fuel sending unit.

I have a 1981 e-350 with dual fuel tanks the p.o. added a third tank and 3 electric fuel pumps along with sepparate gauges and swi
ANSWER : The switch you are referring to is vended with the required electrical and fuel schematic (I just looked in the box) that answers your installation question. If you want an advance view, here is a link as well. Yes, you need a return line and just refer to the aforementioned link. If you are retrofitting back to OEM, I strongly encourage you to buy the original Factory Service Manual (FSM). There are lots of details attending this system and obviously it is difficult to recount it all here. The FSM will make your life much easier and you can then make sure your installation is perfect. Alternatively, YourMechanic can dispatch a certified mechanic and perform the whole retrofit and check out if you desire. Just request and schedule a generic service such as fuel pump service and the mechanic will come to your location and estimate the parts and labor required. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

1996 F150 4.9 5 speed. Frt. Fuel pump quit working. Put fuel in rear tank and it sucked the fuel to the frt tank.
ANSWER : The two tanks are designed to work together and so BOTH pumps must be functioning and, as well, the related fuel system supply code, the Code P0232 that has set has to be resolved. P0232 means that the fuel pump relay is stuck on, keeping power supplied to the fuel pump even after the ignition has been turned off although another possibility is the fuel pump secondary power circuit has a short to battery voltage. The factory service manual (FSM) specifies a very lengthy diagnostic (because you have separate tanks). If you do not have the FSM, your best bet is to request a fuel pump diagnostic – dual tanks and let a certified mechanic get to the bottom of this. With regard to the other code, P0704, that code will set if the clutch switch is defective, there is worn clutch pedal lever or clutch lever bushing, shorted or open wiring and/or connectors in the clutch switch circuit, a blown fuse or burnt fusible link and/or, rarely, a faulty PCM or programming error. If you request the pump diagnostic the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Okay so when I turn my lights on at night my brake lights do not work, when I don’t have my lights on they work fine.
ANSWER : Hi there. Based on your inquiry, it’s highly probable that you have a damaged light switch or some electrical fault inside the turn signal relay. However, it’s also possible that the brake switch above the brake pedal could also be the source of your problem. Due to the fact that multiple electrical components might be causing this issue, it’s a smart idea to first have a professional mobile mechanic complete a brake lights are not working inspection, so they can determine what’s causing all of these issues and recommend the right repairs.

All dashboard lights and tail lights do not work after driving through a lot of snow. Headlights work. And brake lights work.
ANSWER : Hello. We’ll be happy to help you. There are a few things that I recommend checking to discover why your lighting system is malfunctioning. The headlight dimmer switch should be checked. Along with the wiring harness above the right front tire behind the fender well cover. Also
the main fuse under the hood should be inspected because other people with your particular vehicle have had similar lighting issues if that fuse goes bad. It will be a great idea to check the rest of the fuses in that area too while checking the main fuse. Once the fuses are checked inside of the main fuse box then I would check the fuses inside of their interior fuse box. The interior fuse box should be located on the driver side of the dashboard near where your legs would be. If you need more assistance with repairing your vehicle please keep in mind that our organization provides Mobile Mechanics who can help you diagnose and repair your vehicle, all at competitive rates.

No dash lights, back right tail light is out, no parking lights. Brake lights work though as does head lights.
ANSWER : Hi there. In many cases, when you have electrical problems like you’re describing, it’s caused by multiple electrical component failure. It’s likely that a few electrical relays are not working; especially if you have systems that utilize the same components (such as your brake light and tail lights). I would recommend having a professional mobile mechanic come to your location to complete an electrical problems inspection first, so they can pinpoint what is damaged and recommend the right repairs.

Dash, Tail/brake, dome, trunk, glovebox, and door lights won’t work, dash doing weird things.
ANSWER : Hi there. Sure would appear a lot is going on electrically all at once. This could be, a problem in the PDC (power distribution center). The PDC is typically located under the hood and contains numerous fuses and relays. I don’t believe any one fuse will resolve all of the electrical issues. There is a possibility, it is not a power supply issue. It may be, the result of a poor electrical ground common to the inoperative components. Proper circuit testing should be performed. This would confirm the cause of multiple electrical failures. I recommend having your vehicle’s electrical problems be diagnosed and repaired by a certified technician, such as one from YourMechanic.

Can 1 man replace a fuel pump and sending unit, clean out sludge and particles from fuel tank in about 1 hour? Think I was scammed
ANSWER : To drop the fuel tank on your model, and immediately re-install the tank (without any cleaning or service) would require about 2 to 3 hours in total for an experienced professional if a lift is available. The fuel pump itself can be installed without removing the tank but to do that you must have access to the inside of the car because the pump is removed through an access panel under the rear seat. Also, you can’t drop the tank without access to the inside of the car because to drop the tank the wiring harness has to be disconnected and that connection is only accessible from inside the car. So, if the car was locked, obviously no work was performed on the vehicle. YourMechanic does offer these services and you can start by requesting fuel pump replacement. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.