Rear Window Defroster; Tire Pressures & Wheel Alignment - RayTek AUTOPRO Manual De Instrucciones

Rear Window Defroster

Locating Broken Grid Lines
Rear window defroster uses heat through voltage
to defrost the rear window using metal strips
attached to the inside of the rear window. To visu-
ally locate broken grid lines is difficult. To trouble
shoot defroster system grid lines turn ignition on
and activate rear window defroster. Using the IR
thermometer, measure temperature across each
defroster grid line from left to right from inside of
window. Temperature should increase from left
to right on grid line as temperature is measured.
If temperature remains constant across grid
line, check for a loose ground for defroster grid.
Temperature drops will indicate location of broken
grid lines. See Fig. 7. If defroster does not turn on
or temperature does not increase, problem may be
in voltage supply circuit, relay or defroster switch.
See appropriate service information to diagnose
and repair.
Fig. 7: Locating Broken Grid Lines
Tire Pressures & Wheel
Alignment
NOTE: Before trouble shooting tire
pressures or alignment, ensure
all tires are properly inflated to
manufacturer's specification.
Ensure tire size on vehicle is the
same across the front or rear and
that bias-ply and radial tires are
not mixed.

Tire temperatures can tell you how well the tire is
using the tread surface and the road surface to
maintain control. The objective is to get the tire
to work effectively across the entire face of the
tire. This can be maximized for most vehicles by
adjusting tire pressures and alignment.
Tire Temperatures/Pressures
CAUTION: Some vehicles are
equipped with tire pressure
monitoring systems. If air
pressure is adjusted, system
may set a warning light. Check
manufacturer's information before
adjusting air pressure beyond
factory specifications.
Optimum tire temperature should be little to no
temperature differential across the tire tread. On
a vehicle such as a taxi or a truck, this procedure
may not be suitable because of the varying loads
impressed upon the tires.
Tire manufacturers recommend tire temperature
differential for passenger car tires across the tread
should be less than 10°C (20°F).Before test drive,
ensure tires are properly inflated to manufacturer's
specifications. To obtain an accurate temperature
reading, test drive vehicle in a low-traffic area,
preferably on a straight, level section of roadway.
Operate vehicle at a safe speed and bring to a
complete stop. Try to avoid any sharp turns or
movements during test drive. Stop vehicle, place in
Park (auto trans) or neutral (manual trans) and set
parking brake. Using the IR thermometer, measure
temperature at inside, center and outside of tire
tread surface. See Fig. 8.
Fig. 8: Measuring Tire Temperatures