Chevrolet DB90 Series, Service Manual

Page: 216 / 242

S ec. 12-felO _________________________________
CHASSIS ELECTRICAL AND INSTRUMENTS
DK. QREEN (COIL)
TRAILER MARKER
*P RELAY
FEED CABLE
------------------------------------------------------- 1
&"'* 1 ~L
TRAILER CABLE
AND PLUG
INST. PANEL
WIRING HARNESS
FUEL TANK
SELECTOR
SWITCH WIRING
LEFT FUEL TANK WIRE
B
r ig h t f u e l t a n k w ir e
Figui e
2 —Chassis Junctions (Conv. Cab) (Typical)
The
ed and ps
c ir c u its
b reviatioh
co lo r and
a re as foil
^nsulation on each w ire is d istinctly colo r-
tterned to a s s is t in tracing and testing
nd to a s s is t in making connections. Ab-
and sym bols used in w ire insulation
pattern designations on Wiring D iagram s
ows:
BLK. . . . Black
ORG. . . Orange
BRN. . . . Brown
PPL . . . Purple
CH. . . . Check TR.
. . T racer
CR. . . .
C ross YELL. . . Y ellow
GRN. . . . Green
/ /
. . P a r a lle l
NAT. . . .; Natural
WHT. . . White
ENGINE IfARNESS-TO-INSTRUMENT
PANEL HARNESS CONNECTOR
NOTE): Information pertaining to the 3 2 -te r m ­
inal engine harness to instrum ent panel harness
connector u sed on S e r ie s 90 tilt cab m odels
rem ains the sam e as covered in CHASSIS ELEC­
TRICAL AND INSTRUMENTS (SEC. 12), p ages 12-1
through 12-79 in the 1970 Heavy Duty Truck
S erv ice M0pnaul ST135-70 except as follows:
Pow er supply to the engine and cab wiring
h a rn ess qn conventional cab m odels and S e r ie s
90 tilt caty m odels is made through a m ale-fem a le
type connector en closed in rubber.
CIRCUIT BREAKER -SPEED AXLE)
®
1
©
2
©
3
©
4
©
6
®
8
©
8
, ®
9
®
10
©
11
©
12
©
CHASSIS JUN CTION BLOCK T-8003
Figure 3 —Chassis
Junction Block (Tilt Cab M odels) (Typical)
It is recom m ended that this connector, as
w ell a s sim ila r connectors in the w iring h arn ess,
be cleaned and lubricated with a m ulti-purpose
g r e a se w henever the connector is separated or
whenever difficulty caused by corrosion has been
encountered. The lubricant w ill keep m oisture off
the e le c tr ic a l term in a ls and thus prevent c o r r o ­
sion which can cause high r e sista n c e in the sy ste m .
On conventional cab m odels, the 32-term inal
connector is mounted on the upper right-hand side
of the dash panel in the engine compartment;
T erm inal le tte r s shown on w iring connector body
(fig. 1) correspond to le tte r s on w iring diagram s
and in the tabulation which follow s: the tabulation
lis t s each term inal le tte r, the circu it it c a r r ie s,
and the s iz e , color, and pattern of the w ire which
connects to each term inal.
Connector Replacem ent
NOTE: W iring connector term in als should be
checked for proper alignm ent and to ensure that
they a r e properly seated in connector c a v itie s.
1. Rem ove two sc re w s which attach the two-
p o st junction block to the dash panel; then rem ove
two sc r e w s which attach the 32-term in al bulkhead
connector to the dash panel.
2. Insert a 7 /1 6 -in c h socket through engine
h arn ess w iring, then turn retaining bolt out of con­
nector body. Separate engine h arn ess connector
from instrum ent panel h arn ess connector.
NOTE: The retaining bolt w ill rem ain in the
engine h arn ess connector.
IMPORTANT: Mating connectors m ust be a s ­
sem bled straight and slow ly to a ssu r e proper
alignm ent of term in a ls. Tighten bolt slow ly to ap­
p roxim ately 60-inch-pounds torque. W hile bolt is
being tightened, check to be su r e gap between con­
n ectors is uniform .
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT