Originally Posted by djlarson0506
Follow the ground wire from the battery to wherever it lands on the car. Make sure that the connection is clean.
It'* been a while since I've seen her, but on my old 1997 Bonneville, the ground wire goes to three places: a small one to the starter, a small one to the frame behind the battery, and the biggest one to the engine block, about underneath the oil dipstick.
When the valve cover gaskets start to leak with old age, they'll put some natural rust protectant on the engine block ground.
Mainly, if there'* corrosion taking place, it'* a fairly obvious white or green surface on the battery terminal side, which you would have noticed by now.