Dashboard four wheel drive switch

OK a more basic Q. How can you tell that the Explorer is in Auto/ 2 wheel drive?

With the explorer jacked up with a wheels off the ground all 4 wheels turn regardless of the position of the selector on the dash (auto, 4 whl high or 4 whl low).
In soft sand all 4 wheels dig in at the same time.
I understood that the "auto" position would kick in the front wheel drive if the rear wheels slipped or spun. But is there a lag in time or practically instantaneous?

Well, a friend of a friend came up with an answer.
Un plug all elect. Connectors having to do with the system, at the transfer case, above the left, rear wheel well (inside vech) then disconnect the battery (both + & -) wait 5 min. Then plug everything back in and Lastly hook up the battery. This resets the computer to default. Now the rear wheels will turn (milking the clutch very slowly) without the front wheels engaging until the computer senses the rear wheels "slipping" then with a clunk, the front drive shaft and wheels rotate. Well hope this helps some poor soul avoid a week's worth of headache and work as it cost me.

When selecting one of the four wheel drive buttons, there is no response. It worked fine last year.

2002 Ford Explorer Four Wheel Drive

were is it in my explorer

I need to replace the buttons for my four wheel drive, because I believe they are the reason my four wheel drive no longer works. But I don't know where to look for the part. Can you help me?

I don't have any 4X4 buttons or anything and I don't have advance trac. So how does my AWD system work? Correct me if i'm wrong, it has 3 differentials, one in the front, near transmission and in the back. On normal driving conditions, each tire gets 25% of the torque. Lets say the front of the car is on ice and the back on pavement, won't all the power be directed to the front of the car because of the center open differential? Isn't it true the differential sends power to the tire with the LEAST resistance? Or even if one tire gets tons of traction and the opposite tire no traction, won't the ice tire get all the power because, it's called the path of least resistance? I'm just trying to figure out the proper name of my AWD since no electronics are involved. Thanks

Ok, so now lets say the whole right side of the car was on ice and the left was on pavement. The car wouldn't go? Because the tires have less resistance on ice therefore all the power would go to the stuck tires and not the tires with good traction? Also, do you think the rear differential is a limited slip? Thanks

Ohh ok. Thanks a lot for your help. If only my car had advance trac. Too bad it is standard on the models of the explorer 06 and on. :-(