help- door ajar light stays on f250

My "door ajar" light has been staying on alot lately...over the past week or so. I've also been getting a series of beeps as soon as I insert the key and before turning to start the engine. I think I have ghosts.

There's a small switch that is in the door right near the catch. It's a real pain to get at, I have tried to lubricate it with electronic lub but the problem comes back. It cost about $55 CAD for the switch. If your a handy person you can do it yourself (wear gloves, lots of sharp edges). If you have the dealer do it count on another $75 + CAD. It is a common problem. had it with both front doors in my 99 F-250 SD

FYI: I know this is a common problem with mid-late 90's Rangers. Simple solution is to thoroughly spray the door latches with WD-40 while opening/closing doors. The switch gets gummed up and does not operate properly.

Dealers are well aware of the problem and unfortunately you may have to replace the switches.

Yet another $.02 worth from a proud owner of a 2001 Ford Ranger 4x4 and a 1970 Mach 1 351C @

I guess I should've mentioned I have a 99 F-150. It's been happening to mine over the past week or so. Awhile back I posted about another problem...a disappearing odometer. It seems to happen when it's heavy fog or rainy or the air is very humid. The problem does not show when the air is dry.

Some fords (rangers?) 3rd door switch can be a culprit too, and in one schematic I saw it didn't show it at all, yet that was the problem

Most likely you have a wire harness somewhere with poor insulation. When the air is dry there is no problem, but when the humidity is high enough the resistance (of the air) is lower and you have a short. Replacing those wires and/or connectors, or at least wrapping them well with electrical tape, should solve the problem. If I were you, I would look at some schematics to find where those affected circuits have wires and connectors near each other, then inspect those areas of the vehicle.

-D