The brake light is controlled by a little button switch that's mounted high on the brake pedal lever. If you follow the brake pedal upwards with your fingers, you'll feel the button.
It has a spring in the button that pushes the button back out when you release the brake pedal. If the spring jams, the brake lights stay on.
Replace the button switch.
According to the 2003 Mercury Mountaineer Owner Guide : ( DOT 3 brake fluid , meeting Ford specification ESA-M6C25-A )
On your 2003 Mercury Mountaineer : A problem has been detected with the Anti-lock Brake System It could be a fuse , a sensor , or some other problem As long as the red " BRAKE " light is not on in your dash , you still have " normal " brakes * my ABS light suddenly came on and the first ABS fuse I checked was not installed all the way (I don't know how that could have happened ! ) I touched the fuse with my finger , heard a " click " and the ABS light went out ( just lucky I guess , but suspicious )
look in the owners manual. However should be by the emergency brake you have to get on the floor and look up
my check engine light stays on and the o/d light blinks....what could this mean?
That would be the 4.6 liter engine, which takes six quarts. * of 5W-20 according to the 2003 Mercury Mountaineer Owner Guide
I get 15.3 in my 2005.
4
( # 24 ) is a blue color 15 amp fuse for the cigarette lighter and OBD II in a 2003 Mercury Mountaineer ( under the instrument panel )
A problem has been detected with the Antilock Brake System : It could be a fuse , a sensor , or some other problem As long as the red " BRAKE " light in your dash is not on , you still have " normal " brakes
I had the same problem on my 2002 Ford Explorer, after I replaced the gas cap the light turned off
On a 2003 Mercury Mountaineer , 4.6 litre V8 engine : firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of vehicle
I've had that happen on my 02 moutianeer. I got back in and hit the brake and it went out. You could have one of the sockets on your back lights burning out. THat includes the the top tail light also.