I recently bought a 1997 7.3L F350. The truck had not seen a lot of use over the last couple of years and it needed a boost on the day I picked it up. The seller said the first thing I should replace were the batteries because he thought they were shot. After the 2 hour drive home, the batteries were sufficiently charged to start the truck after about 5 seconds of cranking. I let the truck sit for a week and the batteries would still start the truck after 5 -10 seconds of cranking.
Ok, so to my problem. I replaced the batteries with 2 Red Top Optima batteries. The truck started immediately (1 second of cranking). I let it run for about 10 mins and then shut it off. Tonight, I went out to start the truck and all I am hearing is loud click when I try. The batteries appear to have a good charge - 12.86.
My biggest concern at this point is that I have somehow hooked the batteries up wrong and really screwed something up. I did not look at the batteries orientation when I took them out. When I put the back in, I have the passenger side battery in so that the negative is on the left and the positive is on the right (this is relative to standing in front of the truck and looking down on the batteries). The driver side battery is oriented so that the positive is on the left and the negative is on the right. (so this battery is rotated 180 degress compared to the other). The cables are connected so that the positive terminal on the drivers side is connected to the positive terminal of the passengers side. Have I got this wired correctly?
Assuming the batteries are in correctly, I have no idea how the old batteries did not drain over night, but the new ones are.