Hello I'm Aran and I will give you my best effort to try and answer your question completely and to your full satisfaction.

So do you have headlights, dome lights, horn or radio etc.

So the vehicle has no power to anything as far as you can tell is that correct?

Do you have a test light?

a 12 volt test light to check power at different locations

Are you by the truck now?

Has any work been done on the truck recently?

But nothing in the engine compartment correct?

Ok, for the vehicle to be TOTALLY dead there is only a few things that it can be. Have you pushed and pulled on the cables at the battery to make sure that they are tight and do not move?

That would be the first thing to check is make sure the cables are tight on the battery, then follow the black cable to the engine and there make sure it is tight, then follow the red wires and make sure they are tight at their locations.

Can you try this now?

one moment

By the battery do you have a block similar to the one highlighted in the picture?

Full Size Image

Let me ask you this, if you are standing facing the engine, which side is the battery on right or left?

Ok that picture I gave you is of the battery, that junction block is just below the radiator cap on the fan shroud, I am just trying to determine if you have this or not.

So the battery cables are tight at both ends, you checked them at the battery and at the other ends is that correct?

Ok next is the fuse block under the hood, have you looked at all the BIG fuses to make sure they are ok

Full Size Image

So none of the fuses are blown, is that what you were able to see?

Tell me about how you tried to boost it, was it from another vehicle?

When you hooked up the cables did it spark a bit?

Do you have a multimeter?

Have you put that on the battery, and what does it read?

Something is not making sense here, even if the battery is discharged it should still light the dome light or something, the vehicle has NO electrical power anywhere is that correct?

Can you take your meter and go over to the big fuses and touch the top of the fuse with one lead and then ground the other end on metal and see what the meter reads?

Sorry on top of the fuses there is 2 metal tabs touch both tabs one at a time and see what the meter reads with the other lead on metal.

No just we are checking for battery power on the fuses. So put one lead on metal and then touch the two tabs on the big fuses and see if it shows 12 volts.

So they read 12 volts?

So did this issue just start, like it ran yesterday and today it is dead?

What light?

And now there is nothing anywhere?

Do you have a different battery to try?

For the whole vehicle to be dead it either has to be the battery or the cables. Is the vehicle you used to jump start still there with the jumper cables?

Could the jumper cables be bad, if you hook one end up to your battery and then quickly touch the other end does it spark, can you try that?

So touch the cables together quickly to see if they spark.

A big spark or small spark?

which vehicle is the jumper cables hooked up to?

hook them up to your truck and then touch them together and see if it sparks

unhook them from the explorer

how long did you let the explorer run on your truck?

was it running?

So even with the jumper cables hooked up and the explorer running you did not even have a dome light or a radio?

Wow that does not make sense, does this just have one battery?

Try this, at the starter take a screwdriver and there is a big cable and a small wire, touch the two together with the screwdriver and see if it cranks over.

Full Size Image

on the passenger side of the motor, that is the starter motor

sure