Patent ID: 8367927

Claim:
A wire waterproofing method for a wire to be arranged in a water susceptible area of a vehicle, the wire having a core made up of a plurality of strands covered by an insulating coating layer, the method comprising: removing the insulating coating layer in a lengthwise intermediate part of the wire to expose the core, connecting an intermediate crimping terminal to the strands of the exposed core section, by ultrasonic welding, resistance welding or soldering, mounting a heat shrinkable tube on the exposed core section and parts of the insulating coating layer adjacent to the exposed core section, the heat shrinkable tube having an inner layer made of a hot-melt waterproofing agent including a hot-melt polyolefin resin and an outer layer made of a soft resin including an electron-beam cross-linking polyolefin resin, and heating the heat shrinkable tube to melt the hot-melt waterproofing agent of the inner layer and to infiltrate the waterproofing agent into clearances between the strands of the exposed core section, and introducing negative pressure into the inside of the insulating coating layer from an end of the wire to suck the waterproofing agent into the inside of the insulating coating layer and to infiltrate the waterproofing agent also between the strands of the core inside the insulating coating layer.