I have a 2003 2500 with right at 300k. My passenger side battery cap popped off about a month ago and sprayed battery acid underneath my hood. I could smell it when i pulled in the driveway. Batteries were only a couple years old. So I let it cool down, cleaned engine compartment, cleaned all the terminals and connections on both batteries,topped off with distilled water and put the cap back on. Ran great for a couple weeks and then it popped again. No corrosion build up on driver side battery, but positive terminal on passenger battery (the one that popped) was covered in corrosion again. Replaced both batteries with brand new interstates Monday. Cleaned all terminals again before installing. Ran wonderful for a couple days and then the passenger side battery popped already, and is already starting to show corrosion on positive terminal. Is there a good way to test that cable to see if that is the culprit or am I missing something? Alternator is only about 6 months old as well. I replaced the terminals with military style fusion solder terminals about a yr ago, so I don’t think it’s the terminals, but at this point I’m ready to replace them again. Any help would be appreciated.