I have a 2003 GS300. The positive terminal on the battery is corroded and the Lexus dealer tells me that the corrosion has seeped in about 1.5 feet and the only solution is to immediately replace the whole wiring harness. I was also told that it is dangerous to drive the vehicle.

The cost of replacing the wiring harness is more than $7000!

Is there an alternate (lower cost) solution to fixing this problem?
Has anyone had a similar experience?

The car is currently running fine.

Many thanks.