My 83 Surburban, 4x4, 6.2 diesel, no longer starts easily, and testing the two batteries reveals that one is bad. No surprise here: the batteries are ancient off brand 80 Ah units installed by the previous owner.
My guess is that I would be better off replacing both batteries, not just the one that tests bad (correct me if I´m wrong here), and that Delco (the only name brand available here) is to be preferred over locally made batteries despite their higher price (again, correct me if I´m wrong).
But where I am completely clueless is how big of batteries I should get. The manual says simply to replace the batteries with the same size and type as factory original, but that is no help given that I don´t have the originals. Nor does the size of the battery trays, as the trays were added recently to fit the existing batteries.
One advantage I have is that the temperature here never goes below 50F, so I don´t need extra power for sub-zero cranking.
So, what batteries should I get for my beast? I´m sick of begging jump starts.
TIA, Warren Post Santa Rosa de Copán, Honduras