Why would a 1987 Ford bronco lose charge when shut off?

Answer 1

The age of the battery may have something to do with it. An old battery will sometimes lose its ability to hold a charge when idle. Also, if you completely drain the battery's charge on a sealed wet-cell battery (the type sold on all cars after the 1970's) by accidentally leaving the lights on, it will never hold a full charge again. Another common cause is in the cigarette lighter. If a gum wrapper or some other foreign object gets in the cigarette lighter socket, it can slowly drain the battery. The lighting element itself can also be the culprit if it is used a lot and becomes worn.