'99' Explorer won't shift from Overdrive

My '99' explorer won't shift from overdrive. I've checked the button on the shifter and it's good and I also have power to one side of the switch. A few months ago I had to keep trying to push it and it would finaly work, but now it won't work at all and I want to pull a trailer. Any help?

Hi, The wiring from your O/D button runs thru the shifter lever and over the steering column and it will fracture over time due to the movement of the shift lever, this is a common problem, You have to drop the steering column down to access the wiring and make the repairs, Now once you have it fixed, And you decide to tow anything, READ your owners manual, It suggests that you do NOT use O/D when towing,,,,Good Luck, Clay..