My neighbor has a '98 Mercury Sable. She can't get the interior light to stay off. They replaced the fuses but that didn't help. Now she said they are having issues with the turn signals.
I realize this is a Ford forum, but Sable and Taurus is very similar. If you guys can help, she would be very grateful.

 

Is the door ajar light ON in the cluster? If so, the switch inside the door (probably the driver's door) is causing the lights to come on. If it thinks the door is open, the interior lights come on. On my car, I finally pulled the courtesy lamps under the dash and turned off the dome light to make sure my battery didn't get drained. I think the switch needs to be replaced, but I refuse to do that...

There's also a known problem with the flasher switch (which might have something to do with your directional lights). My flashers stopped working after about 7 or 8 years of NON-use. I ended up pulling the switch IN and OUT several times and this seemed to "fix" the problem. I guess the contacts inside got dirty? Turn signal problems can also be burnt bulbs. A burnt bulb can make the directional on the dash blink at a different frequency than normal.

 

Thanks for the info, I'll get her to check today. I do know about 4 years ago the flashers stopped working too and it was hard to get the car inspected.