Bought it last year, 135000 miles.v6, 2wd. Love it. Then one day turn the ignition, nothing, lights, dash all work. Cleaned cables and posts real good, nothing. Several minutes later it cranks up like it should. Happened several times then goes for 6000 miles and about 9 months perfect. Last week it did it again 4 times in a week. Sometimes 2 minutes wait, sometimes longer. No codes appear. What could .it be?.

 

You mentioned "nothing" twice. Does that mean "crank no start" or "no crank no start"?
Do you have a multimeter? How about a probe kit with long jumper wires and with some alligator clips and a 4-awg or heavier gauge jumper cable?

 

No crank, nothing, not a sound. Lights, dash, etc do not dim. Yes I have analog and digital multimeter long wire, and cable. But I don't know what to test

 

What do you get if you try starting it in NEUTRAL, instead of PARK ? I try not to interfere , but heiko may be occupied right now.

There are a few more checks you can try before getting out the big guns, lol.

What we need to determine is whether power is getting to the starter solenoid when the key is turned to the start position.
Either we do or we don't , and we go from there, OK ?

 

First off, I do NOT have any diagram for your 2010 Explorer, all of the followings are for a 2007 (same generation as 2010).
Your starting circuit consists of the following components: A) ignition switch, B) range sensor, C) starter relay, D) starter solenoid, and E) starter motor
Let's look at the diagram flow below:

Thing that usually goes bad the most is the wiring/connectors that requires replacing or cleaning using electrical contact cleaner or 91% isopropyl alcohol.
When it happens intermittently you usually have a bad starter solenoid but let's start from the easiest first so you don't have to get underneath your car to get to the solenoid.
Instead of wasting time testing every components like ignition switch and range sensor, you skip both, just start off at the starter relay.
Look below for the location of the starter relay and next time you start your car do this:



1) pop your hood and remove the lid of your BJB
2) stay close to that starter relay so you can hear
3) find a helper to crank
4) can you hear the clicking sound from that relay?
If your car starts then it doesn't matter. You can only do this test when it doesn't crank.
When you crank but no start and you can hear the clicking sound: possible cause is component C or D or E
When you crank but no start and you can't hear the clicking sound: possible cause is component A or B or C

To find out if you have a bad starter relay you can bench test it (search this forum) or follow below diagram:


Please inspect all the relevant terminals and clean or replace if necessary. And assuming they are all cleaned, the component that fails the most is component D) starter solenoid. If you can't find just the solenoid sold separately (usually around $30) you will have to buy a new starter which will come with the solenoid already. Around $70 at rockauto.
Please do NOT throw part at it yet, test first and find out the outcome of your starter relay producing clicking sound or not then get back to test other component A, B and D.

 

Continue from previous post above. If your component C (starter relay at BJB) makes clicking sound, that usually (but not absolute) indicates that the relay is working fine, but you are still urged to bench test the relay first.
Let's assume your starter relay passes the bench test, next component to test is D, which is the starter solenoid.

When S terminal receives 12v signal from your ignition switch thru range sensor thru starter relay, the solenoid is energized. When it energizes, it connects B terminal to M terminal internally. Note the thick cable at B terminal (circuit SDC02) in red is feeded from your battery 12v post. M terminal is connected to the starter motor at all time and starter motor gets its ground from the metal housing.
Let say your relay clicks, you should receive 12v signal simultaneously at the S terminal shown above. If not, then there is a connection problem on GN-RD (green/red) or BN-GN (brown/green) wire.
While you are at it, get a voltmeter and check the voltage at B terminal (hot at all time) and compare that with your battery 12v post, they should be the same. Use an ohmmeter to check for resistance between the two, should be less than 5ohm.

Now let's take a look at below is Innova 3630 Remote Starter Switch (at )

and below is page 4 of its owner manual:


The remote start switch comes with 2 wire with alligator clips and it does just one simple thing: when you push the button on the remote the 2 wires are connected internally within the remote starter switch. So the S terminal borrows 12V from B terminal to energize the solenoid to tell B to connect to M.
99.99% of auto repair shops will have such remote starter switch, but very few for personal use unless you work on cars all the time. This is the tool to bypass ignition switch and range sensor and starter relay.

What does this switch do in your situation?
Assuming you get good 12v at B terminal (hot at all time), and assuming your starter relay clicks and you also get good voltage from your voltmeter at the S terminal, when you push the remote switch button, your starter motor should crank, if it doesn't still, the remote switch can tell if you have a bad starter solenoid.

Can you just run a jumper wire directly from B terminal to S terminal instead?
Technically absolutely yes, but with the remote switch you don't have to stay under the car, and it's safer than without the remote.

Can you bypass the starter solenoid because my S terminal doesn't get 12V signal?
Yes and do it with care because of high amp that can kill, not just injure, and simply connect B and M terminal together, or battery 12v post directly to M terminal. Use 4AWG or heavier gauge. Don't forget to first turn the key to ON position.

Below is the starter torque specs:

So even if you buy a new starter w/ solenoid, you can replace just the solenoid and leave the starter motor alone.
Still, don't throw part at it yet, just wanted to give you a little preview when your starter relay is in good working condition and what to do next.

 

Do you own a simple test light ?

You can make ONE connection with a simple test light turn the key to start and know right away if you have power there or not.. You can do this alone and SEE the result immediately.. Depending on what you SEE will determine where you go next.

 

Thank y'all so much for taking time and making the effort to help me. I now have several things to test. As follow up, the car has cranked EVERY TIME.since my post. Never thought I would want it to fail to start. But really, I so much appreciate the help!!!

 

Reply back if it doesn't crank again just once. 4 times last week and none this week, you wouldn't want to carry a time bomb with you. There is no guarantee that you can always restart it in around 2 minutes, so don't drive it too far away from home.