I have a 2004 Taurus and have several problems with it. The car unlocks itselfwhenever it feels the needeven if it's not locked to start with. The sensor always says that the doors and trunk are always open. The interior locks do not work. I can only lock the car with the key fob and once again it unlocks itself whenever it feels like it [:@]. I had to have the trunk release disengaged because it kept opening on it's own and now it can only be opened with the key. I was told that it could possibly be my smart fuse but that will cost me $450 and there is no guarantee that that will fix it. I also can't get my money back if it doesn't. Does anyone have any suggestions?

 

Get in the car, close the doors, turn the ignition on... Does your door ajar warning light (and the interior lights) stay on?
If so, you need to lube the door locks. The problematic sensors are inside the latch mechanism. Some have had luck with electrical parts cleaner, others with a spray-lube like 3-in-0ne or WD-40. The WD-40 has worked well for me. Spray into the latch (door) where the striker post would reside while closed. Give each door and trunk/liftgate a generous spray, then open and close a few times.

 

Also, would you describe a "smart fuse"? I have never heard anything being called that in the system. Thanks for the clarification.