Document EvELd2qRp9GyDzRzaD2b3bYVn
BULLETIN
DECEMBER 7, 1976
No. Q90 under brakes
FOR BRANCHES. DISTRIBUTORS AND CUSTOMERS.
CHASSIS AFFECTED ALLENTOWNS^HAYWARD^OAKVILLE
ANTI-WHEEL LOCK WARNING UNIT
(All Vehicles with Anti-Wheel Lock Brake Systems)
PURPOSE To advise that the warning unit can be damaged by short circuiting or grounding'either the warning unit or anti-lock warning light circuit.
RE COMMENDATION Avoid grounding or short circuiting the warning unit oi
warning light circuit when trouble shooting this equipment. Always use a
voltmeter to determine if voltage exists at any point in the system.
i PLAINTIFF'S EXHIBIT
INFORMATION Permanent damage to the warning unit can occur
lithe terminals are grounded or "shorted" while the unit is powered
Damage can also occur if a test light or screwdriver is used to
check for voltage at the warning light by shorting to the side of the
bulb socket. 'Shorts" or grounds of this nature will cause failure
af the warning units Internal components (transistors, diodes, etc.)
and render it Incapable of Indicating a failure in the anti-wheel
lock system.
*4-v
MAC-72
CIRCULATION
Service Manager
-f'
Shop
Foreman
Night
Foreman
Night
Foreman
Inspector
Leadman
Inspector
Leadman
Inspector
Leadman
Unit Over
haul Room
HINTED IN U J > .
Service Operations, Allentown, Pa. U.S.A.
Shop Office
Mack