Gas level sending doesnt work where is the gas level sender located and how to replace on 1988 300e mercedes

The fuel level indicating system is a magnetic type system, which consists of the sending unit located in the fuel tank, an anti-slosh module located on the back of the instrument cluster, and a fuel gauge located in the instrument cluster. The sending unit changes resistance according to the level of fuel in the fuel tank, which varies the current flow through the gauge.The pointer position varies proportionately to the current flow. In this system, the sending unit resistance is low (22 ohms) when the fuel level is low and high( 145 ohms) when the fuel level is high. The pointer of the magnetic gauge remains in position when the ignition is turned to the Off position. On some models, an anti-slosh module is used to dampen out fluctuating fuel signals from the sender. Some vehicles are equipped with a low fuel warning indicator. The anti-slosh module will also actuate the low fuel indicator when the fuel level in the tank reaches 1/16 to 1/8 full.


Do your other gauges/warning indicators work properly with the ignition on? If not, check for power at the fuse panel/fuses.

If they do then partially remove your cluster with connector still installed and check for voltage at cluster connector and gauge. Check continuity of cluster and gauge for ground.

Sometimes the anti-slosh module (if installed) goes bad in the Grand Marquis but not likely.

Sender troubleshooting:

1. Perform test with resistors as follows:

1. Disconnect wiring connector at sender unit, then connect resistor between gauge lead and a suitable ground.
2. Turn ignition switch to On position.
3. With 145 ohm resistor, the gauge pointer should contact the Full mark.
4. With 22 ohm resistor, the gauge pointer should contact the Empty mark.

1. Perform test with fuel sender of known quality as follows:

1. Turn ignition to Off position.
2. Disconnect wiring connector from sender and connect it to test sender.
3. Move float rod away from fuel filter against Full stop position. Wait approximately 30 seconds, then turn ignition switch to On position. The gauge should read on or above the Full mark.
4. Move float rod toward fuel filter against Empty stop position. Turn ignition switch to Off position. Wait approximately 30 seconds, then turn ignition switch to On position. The gauge should read on or below the Empty mark. If gauge works properly replace sender, which involves dropping fuel tank.
   

The sending unit is going to be inside the gas tank so..........

Most likely a defective fuel level sending unit, located inside the tank connected to fuel pump assembly. Theres a possibility that you have a ground issue. So check that first as its easier. If the grounds check out then you have a few options. 1. Pull the fuel pump assembly and clean off the fuel level sender(tons of tutorials online for this). This fixed my problem for 10 months until my pump went out. 2. Replace just the fuel level sender. 3. Replace the entire fuel pump assembly (which should include sender and fuel pressure sensor). And a couple notes. If you have around 100K or more miles then DEFINITELY change the entire assembly. It beats having to do all the work again in the near future. No matter what route you go be sure to replace the fuel pump tank gasket.

In your car only have one fuel pump which is you know where it is, inside the fuel tank only have fuel sender which is send the fuel level signal to the instrument cluster,

Either your gauge is bad or the fuel level sender is. Most likely it's the sender in the gas tank. To replace it you would have to drain the fuel tank and pull the fuel pump/sender assembly and replace. You cannot just replace the fuel level sender with this car, the entire assembly must be changed out.

You most likely have a failing fuel level sending unit which is located inside the fuel tank. The sender wears a bit as the float arm moves up and down with normal fuel level variations and this wear can result in a guage that reads erratically. Many of the fuel level senders are now only sold as a part of the fuel pump module so if it turns out that it is indeed the sender you may have to replace the entire pump module. Hope this helps!

this problem is caused by a defective fuel level sending unit, the sending unit is located inside the fuel tank, u must drop the tank out of the car to replace it, it comes as a fuel tank module which includes the sender and a new fuel pump.

the sensor is located inside the gas tank, you can access the sender from the front of the tank, just make sure the tank is less than 1/2 full or gas will gush out when u remove the sender retainner ring on the tank to remove the sender, u will need the car on a lift to do this...

hello, it sounds like it has something to do with your fuel sending unit located inside your gas tank,on the sending unit it has a float arm that reads the fuel level, some times that float arm gets jammed and wont show your actual fuel level,to fix this with your gas tank at least half full use a rubber mallet or any other object that wont damage the tank and with your key in the start position with the car not running but reading your gages hit the gas tank not to hard but hard enough to lodge the float arm loose, if this is unsuccessful then it will probably be a bad fuel sender location sensor located on the actual fuel sender if that's the case you'll need a new fuel sender. good luck and please send me a update or any questions let me know.

You will need to replace the sending unit, that is really the only thing that will cause this issue