PREVOST H3-41 Maintenance Manual page 250

SECTION 06: ELECTRICAL
2. The four movable vertical tapes should be
located on the screen at the left and right
limits called for in the specification with
reference to centerlines ahead of each
headlamps assembly.
The headlamp centerlines shall be spaced either
side of the fixed centerline on the screen by ½
the lateral distance between the light source
centers of the pertinent
horizontal tapes should be located on the screen
at the upper and lower limits called for in the
specification with reference to the height of
beam centers and the plane on which the
vehicle rests, not the floor on which the screen
rests.
TABLE 1 – VERTICAL BEAM AIM GUIDELINES
Headlamp Nominal
(centerline) Vertical
Mounting Height Aim
56 to 90 cm (22 to 0 Vertical
36 inch)
90 to 120 cm (36 to 5 cm (2 inch)
48 inch) down
120 to 140 cm (48 to 10 cm (4
54 inch) inch) down
3. The nominal vertical aim position on lower
beam headlamps shall be adjusted based
on the headlamp mounting height, from the
ground to the light source center of the
headlamp, according to table1.
4. High beam headlamps are aimed so that the
center of the high-intensity zone is located at
the horizontal and straight ahead vertically
(Figure 87).
5. Low beam headlamps are aimed so that the
top edge (the cutoff) of the high-intensity
zone is at the vertical location as per Table 1
and the left edge of the high-intensity zone
is at the vertical centerline of the headlamp
(Figure 88).
6. The inspection
headlamps shall be with the center of the
high-intensity zone from 10 cm (4 in) up to
10 cm (4 in) down; and, from 10 cm (4 in)
left to 10 cm (4 in) right on a screen at 7.6 m
(25 ft) (Figure 89).
86 PA1621 Maintenance Manual All Series | Revised Sept 2019
headlamps. The
Aim Inspection
Limits for Vertical
Aim
10 cm (4 inch) up to
10 cm ( 4 inch) down
5 cm (2 inch) up to 15
cm (6 inch) down
4 cm (1.5 inch) up to
16.5 cm (6.5 inch)
down
limits for high-beam
06502
FIGURE 86: ALIGNMENT OF HEADLAMP AIMING
SCREEN
FIGURE 87: UPPER BEAM HIGH-INTENSITY ZONE
PROPER LOCATION ON SCREEN
FIGURE 88: LOWER BEAM HIGH-INTENSITY ZONE
PROPER LOCATION ON SCREEN
FIGURE 89: AIM INSPECTION LIMITS FOR UPPER-BEAM
HEADLAMPS
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06504
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