Questions regarding battery/ battery cable. Questions are in the comments.

its hard to say with just a picture if the corrosion was because it was sitting.. or prior damage to the battery top..

bad grounds.. since electrons flow from Negative to positive.. have created all kinds of weird issues with computerized controls and transmissions.. in my 96 ford van.. i added an additional ground connection to Circuit 359.. the ground for a bunch of electronics on the engine.. my transmission shifted so much better.. my van has 540,000 miles on it. this is a test i have been posting for over 10 years.. https://i.imgur.com/kviX0VQ.jpg it can tell how bad the corrosion is inside the battery cables.. blue corrosion will eventually eat the copper.. i have to use stainless steel wire brushes when cleaning them.. i have had the acid just eat brass, copper and regular steel bristles away while i am using it.. who stole my bristles.

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