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.
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