My door ajar light stays on frequently. It seems to be the driver's side door (1997 3-door f150) sensor. If I arm the alarm, it goes off after about a minute or so. Also, when the sensor seems to stick the horn honks twice indicating a door not closed well or window left down.

I am sure the door is closing fully, and the windows are up. What else could it be?

 

Do a search for more info but.....I seem to remember a recent thread about this problem and they said that squirting some WD-40 in the door switch would fix it. Seems that the door switches get dirty or sticky inside and don't make good contact anymore.

 

fiskr,

Take it from me, the best way to fix this problem is to replace the door latch switch on the inside of the door right below the latch. It is a pin type switch that sits vertically and despite the rubber seal around the pin, dirt gets by and prevents the pin from fully coming up after the door is closed. Some people spray WD-40 into the latch until the "WINDOW FLOATS", but that is just a temp. fix and the WD-40 actually will attract more dirt and after a while, the WD-40 will dry and gum up and you will be worse off than you were before. The part is less than $9.00. And can be changed out in about a hour or less.

This does involve taking off the door Panel and taking out the door handle and unscrewing the 3-4 torx screws to remove the latch, taking the latch out replacing the switch and reinstalling in reverse order.

My $0.02

 

The WD-40 works. So what if you have to do it again 2 or 3 years from now? If you replaced the switch, you'd have to replace it again in 3 or 4 years anyway. WD-40 is cheap and if it works you saved yourself a lot of aggravation.