7.4.2. Check of a state and replacement of wires of the battery

The negative wire always has to be disconnected first of all and be connected in the last!

Regularly examine battery wires on all their length on existence of signs of mechanical damages, cracks and progar of isolation, and also corrosion traces. Do not forget that violation of quality of electric connection of contact plugs is capable to lead to difficulties at start of the engine, and also to decrease in efficiency of its return.


  1. Check terminal clips of wires for existence of cracks, signs of loss of copper veins and traces of corrosion. Presence accumulated under the insulation layer near terminal tips of white powdery deposits speaks about development of corrosion and need of replacement of a wire. Check plugs of the battery and clips of fastening of tips of wires for them on existence of signs of deformation, weakening of bolts and traces of corrosion.
  2. The negative wire is always disconnected from the battery first of all and connected in the last. Do not forget to disconnect a negative wire even in case only one positive is subject to replacement.

If the stereosystem established on the car is equipped with a security code before disconnecting the battery make sure that you have the correct combination for introduction of the equipment to action!

  1. Disconnect from the battery old wires (at first negative), then "walk" on each of them till the opposite end and disconnect from the traction relay of a starter (positive) and plugs of grounding (negative). Try to remember routes of laying of both wires for the purpose of observance them at installation of new.
  2. Take the wire which is subject to replacement with yourself in shop as an example. Extremely important factor is compliance of a design of clips of a wire to a form of connecting plugs on the car.

It is easy to distinguish wires from each other on color of isolation, always black at negative and red at positive. Besides, the positive wire usually has bigger section.

  1. Wire brush smooth out a carving on connecting plugs of the traction relay and grounding. After removal of all traces of corrosion slightly grease carving rounds with acid-free vaseline for the purpose of prevention of development of corrosion further.
  2. Connect a wire to the plug of the traction relay/weight and strongly tighten a fixing nut / bolt.
  3. Before connecting a new wire to the plug of the battery make sure that it freely reaches it without excessive tension. Carefully smooth out polar plugs of the battery, then slightly grease them with acid-free vaseline.
  4. First of all always connect to the battery a positive wire, then negative.