Fog lights. Headlights and hi beams can make foggy conditions at night much worse because their light tend to illuminate the fog directly in front of your vehicle. Because Fog lights are much lower on the front of your vehicle don't cause this problem and you can see a bit futher. the fog lights
What I do is put my headlights on ( low beam ) and pull the headlight control towards me to turn on the fog lights ( push the control in to turn off the fog lights )
On a 2002 Mercury Mountaineer : Put your low beam head lights on and pull the headlight selector switch towards you
Turn your low beam headlights on and pull the headlight knob out towards you to turn on your fog lights ( push the knob back in away from you to turn the fog lights off )
The first model year of the Mercury Mountaineer sport utility vehicle was 1997 Did you mean 2005 ?
If you have to hold the headlight switch out to keep the lights on, then the switch itself is bad. The switch should be a fairly easy part to replace.
Those aren't headlights, they're considered running lights or parking lights. I believe that mercury calls this a Light Bar.
instrument panel or controls?
You can view the Mercury Mountaineer owners manuals online at : www . motorcraft service . com ( no spaces ) Click on Owner Guides ( then select your year , and Mountaineer , etcetera )
headlights
a malfunction has been detected ( could be a sensor )
Turn on headlights/parking lights and adjust dimmer control
If your headlights work, but your tail lights don't, your bulbs could be blown. It is possible that you have a shortage in your car.