2005 Jetta Red Battery Cable corroded halfway up cablel. Does entire top box need replacedorcan just the red cable be replaced?

high resistance will burn cable black and melt plastic, new battery connector will be on new connector , starter may be pulling heavy load of amps

HOSE the whole area free of corrosion, then replace the defective cable with a factory style original configuration....wirebrush the negative as it attaches to the frame....check the starter solenoid and use a small wirebrush on that too, to remove corrosion...do not be afraid to BLAST away the corrosion with water~ ECU's and the delicates are shielded from some moisture~

chase with WD-40 if the water is affecting anything WD=water displacer~

And the 40 was the 40th formula they tired before getting what they wanted, developed by the US Air Force to protect and lubricate missiles and other rocket parts. Missile silos are notorious for excessive moisture inside them. And seawater brine on aircraft carriers is horrible on jets on deck.

The top fuse box on some cars is a unit with the cable built in, but on some cars it can be replaced. It is not an expensive part and it is easy t