My positive cable keeps corroding. I clean it, polish it, say prayers over it, and yet in a few weeks it is funky again. My 90 is VERY sensitive to drops in battery voltage and will start to behave erratically to signal me that it is time to look at the connection. First, is there a cause for this, and hopefully, prevention? Second, I looked at rockauto.com for the price of a new cable. $70 for the first design and $100 for the second!!!?? Is that possible??