2003 Ford Windstar POWER WINDOWS

6 MTHS AGO MY PASSENGER WINDOW STARTED ONLY WORKING PART TIME, MOSTLY STUCK IN DOWN POSITION AND IF I HIT THE INSIDE DOOR IN A CERTAIN SPOT IT WOULD GO UP. NOW 2 MONTHS LATER MY DRIVER WINDOW IS DOING THE SAME THING, BUT TO GET IT BACK UP I HAVE TO PUSH DOWN HARD ON THE OPEN WINDOW AND IT WILL EVENTUALLY GO UP. I THOUGHT IT WAS THE MOTOR, BUT WHY WOULD IT ONLY DO IT PART TIME IF THE MOTOR IS GONE? IT IS BECOMING INCREASINGLY WORSE, LIKE WHEN I FORGET ABOUT IT AT A DRIVE THRU AND THEN HAVE TO FIGHT TO GET IT BACK UP! WHAT COULD BE THE CAUSE. ALSO AFTER THE VEHICLE IS REALLY WARMED UP, MY TWO BRAKE LIGHTS GO ON AND STAY ON. I HAVE HAD THAT CHECKED AND THEY FIND NOTHING WRONG WITH IT. I HAD AN 98 WINDSTAR THAT HAD ELECTRICAL PROBLEMS ALSO, IS THIS A COMMON PROBLEM? SHOULD I STAY AWAY FROM WINDSTARS? I REALLY DO LIKE THE VEHICLES, BUT NOT THE PROBLEMS.