My friends grampa has a 96' or so Explorer 400 that from day one has had a battery drain prob. any ideas? The dealar found no prob but every time it sits for more than 2 weeks it is dead. He uses it for fence and farm work, and he is looking at a honda Rancher if I cant get this prob fixed.
Thanks, Joe

 

Has Grandpa ever replaced the battery?

 

it has done it since day one.. it has sucked 3 of them dry..

 

If the Batteries are literally getting dried-up (as in the liquid is leaving the battery) then it looks as if the battery is being overcharged or "cooked".

 

Replace the voltage regulator. The symptoms sound like too high a voltage is being applied to the battery. Place a digital voltage meter on the positive and negative terminals of the battery with the engine running and take a reading. Chances are you are above 15 volts. Radio Shack sells a very inexpensive "multimeter" for under $20 which will measure volts, amps, ohms, and circuit continuity. (a worthwile investment) good luck.

 

If you find over chargeing is not the problem,ypu can remove the negative cable from the battery and hook atest light between the cable and negative battery post,if the light comes on you know there is a circuit drain.

 

it charges at 12.5 V at idle and 12.9 when i rev it up. It defently has a drain.. but I dont know where. I was just hopeing that someone in this form had a simular prob and knew what the problem was. I will search for the drain this weekend
Thanks, Joe

 

use a digital volt meter between the -terminal and the - battery cable and if you see a big draw start pulling wires from the terminal board 1 at a time and see which one causes the reading to change.also does he shut off the key or just the kill switch?

 

It ought to be charging at around 14.5 volts. 12.9 seems too low. Replace the voltage regulator. I don't know how to check the actual output of stator,but if you could find out, I'd do that first. A fully charged battery has over 12.9 volts alone.

 

I put in a new voltage reg. chargeing much better now.. thanks guys...
Joe