GMC 1976 ZEO 6083 Maintenance Manual page 610

4. Remove the (2) panel retaining screws and
remove the panel (See figure 6) .
5. To install, reverse steps 1-4.
CIGAR LIGHTER REPLACEMENT
1 . Remove the element portion of the lighter
from the instrument panel.
2. Disconnect the battery ground cables .
3. Remove the rear instrument panel cover by
removing the (2) screws at each side of the rear panel
cover. Lift rear panel cover up and work out of in-
strument panel.
4. Locate the cigar lighter connector and remove
from lighter housing.
5 . Turn the lighter housing (rear) counter-clock-
wise while holding the front portion, remove the
lighter assembly when the (2) pieces disengage. (See
figure 5)
6. To install lighter, reverse steps 1-5 and check
operation .
SPEEDOMETER CABLE
The speedometer and odometer are driven by a
gear train in the speedometer head, which is driven
through a flexible shaft that is connected to the trans
mission . With cruise control, the speedometer cable
is a two piece cable running from the speedometer
head to the regulator unit and from there to the
transmission .
Replacement
1 . Disconnect the battery ground cables .
2. Remove rear instrument panel cover.
3. Disconnect speedometer cable from head by
depressing spring clip and pulling cable core out of
speedometer end of conduit.
NOTE:
If cable is broken, it will be necessary to
remove lower portions of cable from transmis-
sion end of conduit.
4 . Lubricate cable with lubricant, then push cable
into conduit. Connect upper end of cable to speed-
ometer head and road test vehicle.
NOTE:
Speedometer cable should be lubricated
with AC Speedometer Cable lube ST-700 Part
No . 6478535 or equivalent .
N
CHASSIS ELECTRICAL
12- 5
CIRCUIT BREAKERS, FUSES, AND
FUSIBLE LINKS
GENERAL DESCRIPTION
All electrical circuits are protected against exces-
sive loads which might occur due to shorts or over-
loads in the wiring system . Such protection is
provided by either a circuit breaker, fuse or fusible
link . Each of these protective devices is explained
following:
CIRCUIT BREAKER
A circuit breaker is a protective device designed
to open the circuit when a current load is in excess
of rated breaker capacity . If there is a short or other
type of overload condition in the circuit, the excess
current will open the circuit breaker terminals, thus,
indicating there is something wrong in the system .
The circuit breaker will remain open until the trou-
ble is found and corrected.
FUSE
A common method of protection is to use a fuse
in the circuit. Whenever there is an excessive current
through the circuit, the fusible element will melt and
open the circuit. The fuse is a one-time protection,
and replacement is required .
FUSIBLE LINK (FIGURE 7)
In addition to circuit breakers and fuses, the wir-
FUSIBLE LINK BEFORE SHORT CIRCUIT
FUSIBLE LINK AFTER SHORT CIRCUIT
Figure 7-Fusible Link