Cadillac 60 Series 1963 Shop Manual page 322

ELECTRICAL SYSTEM
12-41
defective. A gage whose needle just touches either
edge of "full" or "empty" marks on the dial may
be considered as satisfactory.
If the dash unit operates incorrectly, the diffi-
culty is due either to dash unit or to wiring from
dash unit to tank unit. Faulty wiring may be
checked by connecting tester directly to tank unit
terminal on dash. unit. If the gage dash unit then
operates correctly, the wiring is either grounded
or open.
An alternate method for testing an inoperative
fuel gage is to disconnect the brown wire at the
connector. When this wire is disconnected, the
dash unit pointer should read above the "full"
mark.
Make certain that the headlight switch is off
when testing with a jumper wire, as accidentally
grounding the lamp circuit wire inside the con-
nector may open the headlight circuit breaker.
Then connect a jjumper wire to the connector and
ground the wire. The dash unit should read below
the empty mark.
Under no circumstances should a hot lead be
connected to the terminal on the dash unit that
leads to the tank unit. If the tank unit is connected
to the battery in any manner, the tank unit will be
burned out because the resistance of the dash unit
is being by-passed.
Although the above tests will show which unit or
wiring is at fault, other checks should be made
before replacing either unit.
Check tank unit for a bent float arm as follows:
1. Establish a fixed reference point when
checking for a bent float arm by placing a straight
edge on bottom surface of cover plate, extending
it outward toward end of float hinge pin.
2. With float arm in "Full" position against
stop "A", Fig. 12-66, bottom of float hinge pin
Full Position
Empty Position
Fig. 12-66 Checking for Bent Float Arm
washer should align with top of straight edge. If
necessary, bend float arm accordingly.
3. Permit float arm to drop down to "Empty"
position, against stop " B " , measuring distance
from bottom of float hinge pin in full position to
bottom of float hinge pin in empty position. This
distance should be from 4-13/16 to 4-15/16
inches, Fig. 12-66.
4. Check for binding and make certain that float
or arm is not touching filter.
When installing a tank unit, make sure that
mounting screws are tight and that unit is
properly grounded.
If gasoline gage does not register when ignition
switch is turned on, check for:
1. Open circuit between dash unit and ignition
switch.
2. Open circuit in limiting coil of panel gage.
If the gage shows full under all conditions,
check for:
1. Open circuit between dash unit and tank unit.
2. Tank unit burned out. Replace tank unit.
3. Tank unit improperly grounded.
If gage shows empty under all conditions, check
for:
1. Wires reversed on dash unit.
2. Loose ground at dash unit.
3. Grounded lead to tank unit or grounded tank
unit rheostat.
4. Open circuit in operating coil.
56. Fuel Gage Tank Unit
Removal and Installation
a. Removal
1. Remove fuel tank as described in Section 10,
Note lla.
2. Disconnect fuel gage tank unit wire.
3. Remove ground wire from tank Unit. Remove
screws securing unit to tank and lift unit out of
tank.
4. Remove fuel strainer from unit.
b. Installation
1. Install fuel strainer on gage unit.