2005 Explorer - Battery Drain

[bobhri]

Two different batteries continuously go dead in 3 days each. When batteries are checked for a draw, there is no drain on battery. Then 3 days later new batteries are dead, Something is turning on when not in use and draining battery. Has anyone had this issue. Sub woofer and amp were disconnected to eliminate any issue there.

 

[ChildIdenticant]

The one that caused this most often from me is the lamp in glove compartment. The plastic of the door weakened of time, just enough so the bulb would turn on. But the door would still look closed this light issue goes unnoticed. .This would create a measureable draw though..
Apologies- My advice is applicable to first gens.

 

[LMHmedchem]

I have read that, ironically, a common culprit is actually a faulty batter saver relay which is located in the cabin underneath the steering wheel. I think your best bet is to get a full charge and then remove the relay for overnight to see if you still get a drain. If that doesn't fix it then you are probably down to removing the fuses one at a time for overnight to see if you can find the circuit that is causing the issue.

Also, you do need to make sure that you don't have a short or bad ground etc. Use a toothbrush to clean the connector ends with warm water and baking soda and then shine them up with a wire brush wheel or sandpaper. Focus on the inside of the connector. Do the same with the terminals and any ground connections that look corroded.

If your batteries have completely drained then they will not hold a charge very well anyway. Sometimes they can be restored with the right kind of charger but that is something to consider. Whenever I change out a battery I check the voltage quite a few times over the first few days to make sure that the problem was just an old battery. If there is something else going on that you don't notice you can end up damaging your new battery.

LMHmedchem