Fuel Gauge Not Working
The Sheerline
fuel gauge was not operating when I purchased "Lady Penelope", so
naturally this had to be remedied. Following is the procedure I followed.
This will be the
same on the Princess.
Problem: Fuel
Gauge not indicating fuel level.
Having previously
checked the operation of the gauge itself and confirming it works and checking
the wiring and found all to be in order, I decided to remove the Fuel tank
sender unit. This is a very straightforward procedure.
Firstly I removed
sufficient quantity of fuel from the tank. Then I removed the clevis pin
holding the handbrake rods at the pivot point on the diff rear housing and
moving the rods aside. Otherwise it would be difficult removing some of the
screws retaining the sender to the tank. I disconnected the wire attached to
the sender. To remove the 6 screws retaining the sender, I first tried using a
stubby screwdriver to remove them. I found it difficult to apply pressure so
the screwdriver would not slip from the lot in the screw. So, using my
1/4" ratchet, I fitted a socket and a suitable screwdriver bit. With that
I managed to apply pressure to the back of the screw at the same time have the
leverage needed to turn the screw with the ratchet. This worked fine. It stands
to reason that it is important to clean the slot in the screws before
attempting to remove each screw.
Once the screws
were removed I gently broke the seal between the sender unit and the tank. The
sender unit came out easily. The task was to determine why the sender was not
working. The reason was obvious - the float arm was frozen in the empty
position (many would say that in these cars the float would spend much of its
life close to that position). I removed the inspection plate on the back of the
sender unit to see if there was any obstruction preventing the arm from moving.
None could be seen. With a few gentle taps on the float arm near the pivot
point, with the handle of my screwdriver (taking care not to bend anything),
the arm began to move. I added a spray of WD40 and worked the arm through its
normal operating arc until it was free. I tested the sender unit using a multimeter set to ohms (the lowest setting possible). The
unit works fine.� New cork gaskets were
made from a sheet then the sender was reassembled and reinstalled in the tank
in the reverse order to removal.
I was told by an auto-electrician - that
if a wire is broken in the sender unit, I could undo a few winding and re-solder.
The few windings would not significantly alter the accuracy (which is often
questionable).
Safe driving
Joe Vavra
14/09/2004