words and images by frank nicosia
Although my 20+ year old ground strap appeared to be in good condition, I decided to replace it just to see if I noticed a discernible difference in the performance of my 1991 Porsche 928 S4...I was really eager to see the results for myself.
Now the old ground strap seemed fairly new and free of corrosion. The visible surfaces gave no indication of any problem lurking beneath the protective rubber covering. As you can see in the photo above, the old ground strap on the top, appears deceptively similar in condition to the new ground strap on the bottom.
A dissection was in order. I brought the old ground strap to my work bench and cut open the plastic sheath just to see how the inside looked. The end connected to battery had a surprising amount of corrosion concealed below the rubber covering, but the other end that was connected to the body appeared brand new inside.
I figured the gasses emanating from the battery must take quite a toll of these things.
As you can see from the photo on the bottom, there was a noticeable increase in voltage, even the dash lights seemed brighter. The TPMS light in the photo looks considerably brighter in the “after” photo (I run non-stock 18” wheels, that's why it's illuminated).
Since many 928s are considerably older than mine, the level of corrosion could be substantially worse. Why not invest 10 minutes of work and a few bucks; the dividends could be huge!