BODY
84
WELDING PRECAUTIONS
Large voltage spikes will occur when striking an
arc during arc welding or cutting operation. These
voltage spikes can easily damage the electronic
modules in the vehicle electrical systems. The
various system used in the vehicle share chassis
ground and therefore simply disconnecting the
battery cables will not provide the protection
required. All electronic equipment must be isolated
from the vehicle chassis ground whenever
performing arc welding or cutting operation on the
vehicle.
Following precautions will minimize the
electronic module damage
Turn off the engine and disconnect the battery
negative (-) terminal before performing any work
on the vehicle.
Before staring to perform welding operation on the
body shell one should always assure that all the
ECU’s are removed.
One should not forget to disconnect all the ground
connections before performing any welding
operation.
(For ground connection details refer
A3 book of electrical section.)
Ensure welding ground clamp is of adequate size
for the welder and the clamp is as close as to the
area being welded.
Make sure that ground clamp make good
connection to the ground surface. Remove any
paints or coatings so that bare metal is exposed at
the ground point.
Ensure that the cable ground side of the clamp
makes good connection with the vehicle if using
one side ground clamp. Do not rely on the opposite
side of ground clamp to make the ground
connection.
Do not route welder electrical cables directly
across from or near any of the vehicle’s electrical
wiring harnesses.
CRUMPLE ZONE
FRONT CRUMPLE ZONE
Crumple zone is a design feature of vehicle for the
safety of passengers in case of collision. Vehicle
frame has crumple zone at the front end.
The
crumple zone,
also known as a
crush zone
,
is area of a vehicle which is designed to deform
and crumple in a collision. This absorbs some of
the energy of the impact, preventing it from being
transmitted to the occupants.
The primary function of crumple zone is to absorb
the energy from a collision and the secondary role
of slowing the actual force of a collision.
Crumple zone is designed to 'crumple' under
impact
, rather than retain their structural integrity
and therefore resist the force being applied to
them. This means that only this smaller area of the
vehicle crumples in case of collision, keeping the
passenger area intact.




