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Ghost Lights

I bought my son a 99 Grand Marquis for his first car. It is in great shape with no body damage and 77 K miles. Problem has been that the interior and head lights come on at will. For what ever reason they just come on and it has caused the battery old and now the new one to discharge.

This is a great running car and is fairly safe for a 17 yr old to drive.

I need help. I have been told that there is a short in one of the doors and it is sending a message that someone is entering the car therefore to turn on the interior and head lights. Could this be a faulty relay or loose fuse?

If not how can I fix his ride???

Many Ford products of that era suffer from the same problem. It is caused by a faulty door switch. Unfortunately, one of Ford’s better ideas is to bury the switch inside the door rather than place it in the door jamb or body like everyone else.

The usual fix (without disassembling the door) is to spray the switch with copious ammounts of WD-40. Since you may not know which switch is misbehaving you should treat all four switches.

how do you spray the switch if it is inside the door?

There are small openings with which to insert the wand. Aim is another problem.

Does this car have a keyless entry pad on the driver door? If so, this is likely your problem. It is a great feature, but the pads tend to decay and start to leak after a decade or so. The lights come on when you touch a pad key or it shorts due to moisture. The solution is to replace the pad and it is pretty easy.

For a short-term fix, I believe that the headlights do not come on if the autolight feature is not engaged. You would also need to pull all the interior light bulbs.

They are great cars and you might be able to put another 200K on it if you don’t get tired of it first. Got more kids that will be learning to drive?

Surf on over to for lots of info and discussion about this car.