If your battery is going dead over nite you need to look for parasitic draw. The door switched do NOT directly control the dome lites anymore. It is down through a computer module. The switch is the input and the lite is the out put. If the switch is bad the computer should still be smart enough to turn the lite OFF after a few minutes to save the battery. You have to isolate the parasitic draw to a specific circuit and repair that circuit only. You'll need a schematic and a DVOM or a clamp on low amp probe. 50mA is about the limit. Anything more than that after about sitting idle for 20 minutes is going to pull the BATT down depending on the RC of the battery. The vehicle is a computer network on wheels. Very few things are done directly these days. Most functions are computer controlled. If the computer ignores inputs or enables outputs when the correct input isn't present you have problems. What if the computer commands the IPC to do things it's not supposed to do? The IPC is going to follow instructions from the BCM. The IPC doesn't ask questions. It just does what it is told to do by a computer. You have to know what computers you have and what functions each one takes car of. The figure out if the inputs are there when they shouldn't be. If the inputs are correct the computer has gone crazy or the wiring harness is bad.

 

40 minutes to be exact. If however the switch breaks and makes contact again, even momentarily, the 40 minutes countdown restarts.

 

A switch that activates itself after the vehicle has been setting idle is a hard problem to find. You may need voodoo to fix something like that, but you do have to start somewhere. You have to think about the problem and what circuits and modules are involved. This requires a schematic and the ability to read it. Sometimes you have to use process of elimination. Unplug something and leave it set to see the result. If it's not the result you're looking for try another device. Or you can use a scope on auto-trigger to look for a glitch on a suspect circuit that only happens once in a while AFTER the vehicle has gone to sleep. You still need a starting point. Which inputs could cause this output? When is the input present? Is it present when it is NOT supposed to be present? These are some of the questions you have to ask yourself. Not easy to find. I would check TSB or look for flash updates on the Motorcraft website on this one. You can also try identifix. They have a large database of fixes and can sometimes lead you right to the solution.

 

First, I wanted to comment on everyones support from the original post to my recent inquiry. I wish I would've found this website earlier when I was driving my Ranger and needed a second opinion for some electrical work.

After doing some further research I found that if the truck doesnt start right away, it helps to place the key in the ignition and swithing it on and off (without cranking it all the way). After several attempts (it took 20-30 times of doing this) the truck finally started up.

I found that if your igition switch has a bad connection due to corrosion, it could make it difficult to start during cold weather. By doing this procedure it can losen the part and allow it to make the connection and fire the motor.

I realize that I cant count anything else out.. Im in the process of moving and dont have my volt meter with me, but later today a buddy of mine will bring his meter over and we'll find out where the real problem is.

Its sounding more and more like a starter issue, however like a previous post mention, cars are moving computers and it becomes more and more difficult to troubleshoot problems. I know this thread and site help me troubleshoot my issue and hopefully this will help someone in the future!

 

A faulty ign sw can cause ALL KINDS of problems(cold weather effects starting more). The key sw has 4 positions(ACC/OFF/RUN/START). Different circuits are functional in each of the 4 different posticions. You need a schematic to find out which. If you have battery drain(Key OFF) you need to look at the schematic to see what has power when the key is OFF. You be surprised to find more things than you expect will still have power in the OFF position. The will be labeled "HOT at ALL times" on the schematic diagram. Only circuits labeled HOT at ALL times should be HOT when the key is OFF. In other words HOT at ALL times is another way of saying the key sw is OFF. If a circuit that is NOT lableled HOT at ALL times on the schematic is HOT when the key sw is OFF that is a problem. Something is getting power that shouldn't and it can drain down your battery over night. If you don't have that problem you need to look for a module that isn't falling asleep(advanced level troubleshooting) which will also drain down the battery. You need to locate the computers(Alldata or Mitchell) and start unplugging them one at a time or start checking fuses for current flow that isn't supposed to be there. If you can find this you then zoom in on that area and start breaking the entire circuit up into individual components until you find the one that is at fault and replace it or you find a wire that is shorted. A wire that bypasses a LOAD is a short. You don't have that kind of short. A short can be a break in the insulation that puts power on a wire that shouldn't have power at this time. It may use power at other time, but not right now. The wiring harness is damaged. The vehicle may have been wrecked. Ground wires can get shorted to ground(vehicle chassis) the same way and complete a circuit that shouldn't be complete at this time. These are the kinds of things that can happen.

 

I need to clarify HOT at ALL times. It means it is HOT not only when the key is OFF, but also when the key is in ACC/RUN/START. In other words it is HOT regardless of what position the key is in and that includes the OFF position. Somethings do have power when the key is OFF. Not much, but you're concerned about the time when the key is OFF which is when your battery gets drained down. You probably don't have to worry about the circuits that are labeled HOT at ALL times since you already know they're HOT even when the key is OFF. It's the circuits that are NOT HOT that are causing your problem because one of these circuits must be HOT when it should NOT be HOT with the key OFF. This is the circuit you're looking for.