My 2002 Ford Explorer XLT 4x4 starts just fine. Shut it off / start it, no problems. Then one time you shut it off and the battery just clicks but the vehicle won't start. The gage on the dash looks fine and the battery light is not on. Put in a new battery and starts right up. Drive down the road for maybe an hour, go in for coffee, come out, won't start. Get a jump start from guy parked next to me and starts right up and runs fine. Gauges all look normal. Stop for a rest break, come out, won't start. Put in a spare battery and off you go down the road again. Happens about twice a month and getting more frequent. Had alternator checked, twice told it was good. 70,000 miles on it. Any suggestions?

 

check the battery cables for corrosion, inside the plastic cover as well.

Clean all connections, battery, starter, engine ground.. sounds like you have high resistance somewhere.

 

Next time it happens, turn on the headlights. If they're bright, you've got a starting system problem; if they're dim, something is draining the battery and you need to get the electrical system checked out.

Steve

 

As aquanaut said, check the battery connections closely. Next time it won't start, have someone put some force on the cables/terminals when trying to start it to see if that makes a difference.

 

Does it only fail with a hot engine. If so, it could be the starter heat sinking also.

 

Same problem. I took mine to a Ford dealer and they put a new alternator on. I haven't driven it enough since then to know if it is fixed correctly. 76,000 miles