Check the clamps on the ends of the wires for corrosion. The presence of white flakes under the insulation indicates that the wire is corroded and needs to be replaced. Check the clips for deformation that reduces the contact patch with the battery terminal.
Replace the battery wires as follows:
First, disconnect the cable from the negative battery terminal, move it aside and insulate it to prevent accidental connection to the battery.
Attention! Even if only the wire connected to the positive terminal needs to be replaced, disconnect the wire from the negative terminal of the battery first.
After disconnecting the wires from the battery, disconnect them from opposite sides.
Pic. 15.1. Connection point «mass» wires to car body
Disconnect the wires from the starter traction relay, fuse box and «massive» wires from the body and the power unit (pic. 15.1).
Mark the location of each wire to ensure the correct installation of the new wire.
When replacing wires, use new wires with the same gauge and length as those being replaced. The positive wires are usually red and have a larger cross section (diameter), and the negative ones are black and their cross section is smaller than the positive wires.
Clean the threaded contact of the starter relay with a wire brush. To protect against corrosion, apply a thin layer of petroleum jelly to the battery terminals.
Attach the battery clamps to the new wires and secure them with a bolt and nut, tightening them very securely.
Before connecting a new wire to the battery, make sure that the wire is not under tension.
After installing new wires, connect the wire «masses» to the negative battery terminal.