Maybe there is a “short” or Drain on the system, Remove Neg Battery cable from the battery & connect a Multi-meter. One lead to the Neg post & the other to the Neg cable, dial in the 2000 ma range and you should read a ZERO or close to it, if you see some drain, simply start pulling fuses one at a time & watch the Multi-meter till you find the culprit I have tried everything, something is killing the battery within 3 days. I am unplugging the battery every night to stop the drainage. I have been trying to solve this problem for 9 months. Any help will be appreciated. Steve 1969 1600