On some units of support equipment, the headlights
have only one filament; instead of blade connectors for
a bayonet plug, they have screws for connection of the
Four headlights (two on each side) are used on
some modern equipment. The inboard units have the
numeral 1 embossed on the lens; the outboard units
have the numeral 2 embossed on the lens. The No. 1
unit has only one filament and a two-blade connector.
The No. 2 unit has two filaments (as in the single unit
described above) and a three-blade connector. When a
high beam is selected, the inboard unit provides a high
intensity, far-reaching beam, while the off-focus of the
outboard units illuminates the area directly in front of
the vehicle. When the lights are switched to low beam
(dimmed), the inboard units turn off and use only the
low-beam filaments of the outboard units.
To align the headlights, various types of special
alignment equipment may be used. Always follow the
equipment manufacturer's instructions for their use.
Some models will provide details on aiming headlights
When it becomes necessary to replace a sealed
beam unit, remove only the screws or springs holding
the unit's retainer ring. Do not move the alignment
screws (fig. 6-94).
Figure 6-93.--Cutaway view of a sealed beam headlight.
1. ALIGNING SCREWS
2. RETAINING SCREWS
Figure 6-94.--Sealed beam headlight installation.