2001 Ford Explorer

2001 Ford Explorer 6 cyl Four Wheel Drive Automatic 86000 miles

I have a 2001 ford explorer sport. I have had it for a couple of years now. When I wish to use the 4 HI function, I switch the controller but the 4 HI does not engage until it hits 25 mph. Recently, it has not been engaging at all, or has been engaging when it wants to. 4 Low also does not work as well. Could there be an electrical problem withthe switch, because sometimes it works and sometimes it doesnt. Thanks for the help.
December 15, 2009.

Chances are the actuator on the transfer case is coing bad. To determine if that is the problem, you need to check if the actuator is getting power when it isn't working. IF it is getting power, replace the actuator. If there is no power to it, then work your way back to the switch.

Let me know if you have other questions.