fuel gauge

87240DLWagon · Post by **87240DLWagon** » 26 Oct 2006, 23:12

My gas gauge dose not work, DOse any one know a common reason for this. Or any suggestions on how to fix it?

Thanks

Post by **billofdurham** » 27 Oct 2006, 12:23

Usually the sender unit in the tank is faulty.

This can be checked as follows:

First check the leads at the tank and at the rear of the gauge to make sure they are clean and secure.
Switch on the ignition and use a test light to check that there is current on the feed side of the gauge. If they are in order proceed as follows.

If the gauge reads empty permanently:
Disconnect the lead on the tank sender unit and insulate it so it cannot ground against the body or tank.
Switch on the ignition and the gauge should read full.
If the gauge still shows empty disconnect the lead on the gauge that goes to the tank sender unit.
Switch on the ignition and if the gauge now reads full there is no fault in the gauge and the wiring or the sender unit must be suspect.

If the gauge reads full permanently:
Disconnect the lead on the tank sender unit.
Switch on the ignition and ground the lead.
If the gauge now reads empty the lead and gauge are OK and the fault is in the sender unit.
If the gauge does not show empty during this test disconnect the lead at the gauge.
Ground the contact on the back of the gauge using a piece of wire. If the gauge reads empty it is OK.
If the gauge shows anything but empty on this test the fault is due to either a dirty contact on the terminals between the gauge and the lead to the sender unit or a break in the lead.

It is very rare that a fuel gauge will fail.

Bill.

87240DLWagon · Post by **87240DLWagon** » 27 Oct 2006, 13:34

wich lead on the tank sender do I disconect? I disconected each one and then I did a number of combonations but none of them afected the fuel gauge.

Also how do I get to the back of the gauge panel? I cant pull it out far enuf to get to the wires on the fuel gauge. Do I have to remove the steering wheel?

Thanks

Post by **billofdurham** » 27 Oct 2006, 16:00

The lead from the sender unit to the gauge should be coloured grey.

To remove the instrument panel there is no need to remove the steering wheel, just the covers around the steering column and then the bracket retaining screws allowing the bracket to slip down the steering column.

Next remove the panel retaining screws (x4) and, if a speedometer cable is fitted disconnect that (I say 'if' as some of the later 240s had an electronic speedo). Hold the rear of the speedo and press the panel up and out until the upper clip is released. Disconnect the electrical connections as needed.

Bill.

wojeepster · Post by **wojeepster** » 01 Nov 2006, 18:14

whap the top of the dash over the gage and see if the gage jumps to life. Our 740 does this. It seems to get stuck. When the car is running one whap fixes it (until next time)