A jargon: "horn does not ring light does not shine, the bottom find fault", it means that when disorder motor vehicle electrical system, insurance device first to check the driver's seat the following.

   Electrical safety device of motor vehicles into the fuse (across the fuse, fuse, fuse) and double metal sheet protector two, it is an important part of the entire vehicle electrical system, its function is when the circuit is short circuited, quick disconnect circuit, protection of wire and electrical from destruction.

   The common faults of fuse type safety device:

   1, the fuse is no protection function. The fuse material for tinned copper or tin lead alloy (tin lead 75%, 25%), which is in series with the total circuit or circuit. If the appliance exceeds the rated load current is more than 20% electrical burn proof fuse, doesn't the role of insurance. It is often because of the fuse from coarse. In the vehicle running, sometimes suddenly fuse fuse, the driver can not find the fuse the original specifications, some readily with coarse wire wrapped around a few turns instead, even when the circuit is expanded in a resistance, light is the formation of electrical pressure drop is too large, resulting in poor start, the heavy electrical equipment destroyed. As an emergency measure (generally not allowed), when the fuse, namely the use of copper wire is replaced, only available multi strand copper wires in place of fine copper wire. If the fuse diameter is 3.14mm, only available 0.8mm diameter copper wire instead of; if the fuse diameter is 2..34mm, only available 0.6mm diameter copper wire instead of.

   2, the fuse has burned, the main source of motor fuse:

   1.Sudden short circuit.Caused by the excessive current.

   2.Fuse assembly.For example: between fuse holder and the socket loose, current generated by the jump fire; fuse fastening screw too tight, the fuse was crushed and even local fracture; fuse with the fastening screws are tightened and maneuver, so the insurance wire diameter became thin.

   3.Circuit overload.For example, many electrical appliances at the same time, overload operation, expansion of the electricity load, a new.

   4.Fuse diameter is too small.The fuse has blown disorder, to pinpoint the source fault as soon as possible and the attack site, and immediately ruled out, must not rashly use bold fuse diameter to avoid the "fuse" means, otherwise attack appliances may because of overload operation.