GMC 4000 Series Service Manual page 530

pry lock on terminal clips down to assure a firm
connection when terminals are inserted into the
connector.
1. P ress terminals into mating end of connec­
tor, then check to make sure terminals are firmly
engaged in connector by attempting to pull apart.
2. Connect mating ends of connector and check
to be sure all lock tangs are firmly engaged by
attempting to separate.
FUSE BLOCKS AN D FUSES
A bulkhead fuse panel provides power take­
offs and fuse clips for appropriate circuits. The
engine wiring harness connectors are bolted to the
fuse panel.
Fuse and circuit breaker block on all conven­
tional cab models is located behind the dash com­
partment door. Block on cowl models is located on
the cowl panel near the center and is accessible
from under dash panel. On all steel tilt cab models
the block is located under left end of dash panel.
Two 4-ampere fuses are used to protect the
ammeter. Fuses are located on fire wall near
fusible links (fig. 3).
All models have two flashers — one for turn
signals, and one for hazard warning signals. In all
models, the hazard signals are wired independently
and can be turned on when the ignition is off. Flash­
ers are located at fuse block. Refer to rear of this
section for information pertaining to the flasher
circuitry.
A typical fuse block used on Series PS-4500 is
shown in figure 4. A typical fuse block and circuit
breaker mounting used on Series "E" and "S"
Models is shown in figure 5, and a typical fuse
block used on steel tilt cab models is shown in
figure 6.
G M C S E R V I C E M A N U A L ________________pfge5i9
CHASSIS ELECTRICAL AND INSTRUMENTS
Figure 4 — Typical Fuse Block (PS4500)
breakers, or flashers, be certain replacement is
the same part number as defective component.
links are located under hood on cowl in the major
wiring harness feed circuit. The fusible link(s)
(fig. 3) is incorporated as part of the wiring sy s­
tem to provide increased overload protection to all
electrical circuits, except the starting motor cir­
cuit, which are not otherwise protected by fuses.
sizes sm aller than the sm allest feed wire; for
DIRECTIONAL
SIG N A L FLASHER
IMPORTANT: When replacing fuses, circuit
FUSIBLE LINKS
On some models, one or two replaceable fuse
The fusible link is a wire of at least four gauge
D O M E LAMP
COVER
A/C CIRCUIT'
BREAKER
Figure 5 — Fuse Block and Circuit Breaker
"S "
M ounting ("E " and M o d els) (Typical)
2-SPEED AXLE
CIRCUIT BREAKER