Electrical Issue

[DrHalfHand]

Here's a puzzle for you all:

Every so often my 2003 4.6L V8 Explorer Limited won't start: when I turn the key it's as if the battery were completely dead. However, if I quickly disconnect the negative battery cable and then reconnect it then it'll start up on the first turn of the key. Basically my solution up until now has been to "turn it off and back on" to see if it fixes the problem.

Any idea what could be causing this? Something electronic that gets stuck open or shorted that then is released when the battery is disconnected?

 

[fordysenior]

Maybe corrosion between the battery post and cable. Clean them. And that corrosion might not be easily visible. Clean them, retighten the bolts on the cables.

 

[Mbrooks420]

Could also have a bad cable.

 

[imp]

@DrHalfHand

Acid from the battery finds it's way under the connections at the terminals, corrodes them (the posts and "grippers" around them), and can eat it's way up into the strands of individual wires quite a way back into the cables. This reduces both the cables' ability to carry heavy starting current, as well as handle the very high surge present at the terminals just as the key is turned.

If limited to terminals, thorough cleaning AND greasing with Vaseline will cure it. Otherwise, replacing cables is the best route. imp