Break lights mercury marquis
Your brake light switch on the brake pedal is out of adjustment or broken.
Is there a adjustment on the grand marquis for the switch on break pedal.
The easiest way is to replace the switch. All you need is the switch (under $20 from Ford), a pair of needle nose pliers, and a cotter pin. It takes about 15 minutes to do. Pull the cotter pin, unplug the pigtail from the switch, then slide the switch off the pedal hanger rod. Slide the new one on, being sure to capture the brake pedal arm between the 2 ears of the switch, plug it in, and put the new cotter pin in. Job done.
I forgot something important. Do NOT use your cruise control until the lights work properly. It is the lights coming on that cause the cruise to cancel under braking!
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