I just purchased this Explorer at a auction. Great looking and great running SUV. One problem, the owner's manual was not in it. The driver side turn signal does not work. Everytime I was go to signal to the left, I hear what you could consider a "buzz" from the area of the turn signal switch. Could this be telling me that a bulb is burnt out. I did the old trick of "bumping the switch" and the rear turn signal works, but not the front. Need your help to see if I need to replace the front bulb or the whole turn signal arm. Thanks!