Chevrolet 1977 light duty truck, Руководство по обслуживанию

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ON-VEHICLE SERVICE
MAINTENANCE AND
ADJUSTMENTS
M a in te n a n c e o f the lighting units and wiring system
consists o f an occasional check to see th at all w iring
connections are tight and clean, that the lighting units
are securely m ounted to provide good ground and that
the h ead lam p s are properly adjusted. Loose or corroded
connections m ay cause a discharged battery, difficult
starting, dim
lights, and possible d am ag e to the
g enerator. W ire harnesses must be replaced if insulation
becomes b urned, cracked, or deteriorated. W henever it is
necessary to splice a wire or rep air one that is broken,
always use solder to bond the splice. Always use rosin
flux solder on electrical connections. Use insulating tape
to cover all splices or bare wires.
W h e n replacing wires, it is im portant that the
correct size be used. N ev er replace a wire with one o f a
smaller size. Fusible links in the w iring are four gauge
sizes smaller th an the cable it is designed to protect. The
links are m arked on the insulation with wire gauge size
because o f the heavy insulation which makes the link
a p p e a r a heavier gauge than it actually is.
Each harness and wire must be held securely in
place by clips or other holding devices to prevent chafing
or w earing away the insulation due to vibration.
By re fe rrin g to the w iring d ia g ra m manual, circuits
m ay be tested for continuous circuit or shorts with a
conventional test lamp or low re a d in g voltmeter.
H E A D L A M P A D J U S T M E N T (Fig. 8-2)
T he head lam p s must be properly aim ed to obtain
m ax im u m road illumination. W h e n using mechanical
h e a d la m p aimers, follow m a n u fa c tu rers instructions.
T h e head lam p s must be checked for p ro p e r aim
w henever a sealed beam unit is replaced and after
repairs o f the front end sheet metal assembly.
Regardless o f the m ethod used for checking
h ead lam p aim, the truck must be at norm al weight, that
is with gas, oil, w ater and spare tire. Tires must be
inflated to specified pressures.
Some states have special requirem ents for h ead lam p
aim ing adjustm ent and these requirem ents must be
known and followed.
Horizontal and vertical aim ing o f each sealed beam
is proveded by two adjusting screws visible through the
bezel which move the m ounting ring against the tension
o f the coil spring (fig. 8-2).
There is no adjustm ent for focus since the sealed
beam unit is set for focus during m an u factu rin g
assembly.
Fig. 8-3- Front Lighting (C-K Models)
left
VERTICAL
AIM SCREW
H O R I Z O N T A L
A I M SCREW
R i g h t side s h o w n ,
side is s i m i l a r .