When I engage the switch on the dash, I can hear clicking sounds coming from under the dash. I am assuming the clicking is a silonoid or relay. Sometimes I can disconnect the battery cable for a couple of minutes and then try again with success. The problem has been going on for some time but this time of year I notice it a lot more. How does the 4-wheel drive engage? Could i be right on my guess?? Help!!!!!

I have a 99 explorer-basically the same drivetrain. there is an electric motor on the transfer case that engages the four wheel drive. it you can hear the motor engaging; which you should as they are noisey, then your problem is in the transfer case. if so, like it was with mine; the fork inside the transfer case broke. Forty dollar part, and an afternoon pulling the transfer case, swapping forks, and intalling it. all in all not a bad job.

yes its silonoid replace