Chevrolet 10 1971 Series Chassis Service Manual page 388

ELECTRICAL— BODY AND CHASSIS 12-2
aiming is even more important because the increased
range and power of this lamp make even slight variations
from recommended aiming hazardous to approaching
motorists.
The headlamps must be checked for proper aim when­
ever a sealed beam unit is replaced and after repairs of
the front end sheet metal assembly.
Regardless of the method used for checking headlamp
aim, the truck must be at normal weight, that is with gas,
oil, water and spare tire. Tires must be inflated to the
SEALED BEAM UNIT REPLACEMENT (Fig. 3)
1. Remove bezel retaining screws and bezel.
2. Disengage spring from retaining ring.
3. Turn headlamp unit to disen9age assembly from
headlamp adjusting screws.
4. Disconnect wiring harness connector located at rear
of unit in engine compartment.
Do not disturb adjusting screw setting.
NOTE:
5. Remove retaining ring and headlamp from mounting
ring.
6. Position new sealed beam unit in mounting ring and
install retaining ring.
The number molded into lens face must
NOTE:
be at top.
Fig. 1 — Fuse Panel
specified pressures.
Some states have special requirements for headlamp
aiming adjustment and these requirements must be known
and followed.
Horizontal and vertical aiming of each sealed beam is
provided by two adjusting screws visible through the
bezel which move the mounting ring against the tension
of the coil spring.
There is no adjustment for focus since the sealed beam
unit is set for focus during manufacturing assembly.
SERVICE OPERATIONS
7. Attach wiring harness connector to unit.
8. Install headlamp assembly in panel opening, twisting
slightly to engage mounting ring tabs with adjusting
screws.
9. Install retaining ring spring then check operation of
unit and install bezel.
PARKING, CLEARANCE A N D IDENTIFICATION
BULB REPLACEMENT
1. Remove retaining screw(s) and lens from housing.
2. Replace bulb and check operation of unit.
3. Install lens and retaining screws.
PARKING LAMP HOUSING REPLACEMENT (Fig. 3)
1. R em ove headlam p bezel on P s e r ie s tru cks.
10-30 CHEVROLET TRUCK SERVICE MANUAL