My son is in college and I gave him my 2007 Ford Explorer Sport Trac. Over the past several months it has had intermittent starting problems (has never done this in the 6 years I have owned it). Once a week or so, after driving for some time, the car will not start (after getting gas, going to the store, etc.). When the key is turned over, all lights come on but no cranking sound. Then if the car is jumped, it will start. Car has a new battery (2nd new battery), new alternator, new gear shift, and yet no mechanic has been able to pinpoint the problem. The problem is not consistent but happens enough to strand my son - keeping him from school or his job. Could this be a ignition switch problem or perhaps a bad cable connecting the battery & starter? At this point I feel as if we are at an impasse because we are now at our second Ford dealership and, of course, they have problems recreating the issue.
This is the easiest thing to check and it’s definitely where I would start. The vehicle is 12 years old now, I could easily see one of the ends of the cables not being as tightly connected as they need to be. Make sure they check the main battery ground to it’s grounding point too.
Being intermittent, Only when warm, Time passing between the no start and the jump start.
I’m leaning towards a failing starter solenoid, I’d replace starter.
I had a sport Trac that would do the same thing and it turned out to be an inertia switch on the passenger side . You can tell the switch was going bad because the wires were starting to melt. I just bypassed the switch and no more proplems.