Power lock, Dome Light & Remote/Fob Issues

[Jim_Philly]

I recently purchased a 2002 FX4 automatic. It has a few electrical problems that might be related:

- Dome light will not turn on after vehicle sits for a while / overnight. After driving it for a while, the dome light works again.
- Remotes lose their programming after a couple of days, and I have to re-program them using the 8-turn lock cylinder procedure
- Power locks also don't work intermittently, usually at the same time the dome light isn't working, but not always. Sometimes the remote works but the door lock switches don't!

Any ideas? Is there a common control module all of these things run through?

 

[Jim_Philly]

Well, I mostly solved my issue. Some WD-40 in the driver side door mechanism worked. I guess it was getting stuck and telling the truck the door was open when it wasn't and so after the timeout period the dome light and keyless entry would shut off. (Still not sure if the door lock issue is related).

 

[Jim_Philly]

Just kidding. The issue is back.

Although it does seem like somewhere along the line the truck thinks the door is open and so it shuts the dome light and keyless entry off to save the battery from draining...

 

[Dirtman]

I dont know how the supercabs work, I assume they still only rely on the main door latches for sensors. If they do they are 12 volt constant and get grounded when the door is OPEN. If you can find the wiring diagram easiest thing to do would be to check right from the wires between the door and cab inside the rubber bendy sleeve. See that you can get 12+ first of all and then see if you have ground while open.

 

[Jim_Philly]

I dont know how the supercabs work, I assume they still only rely on the main door latches for sensors. If they do they are 12 volt constant and get grounded when the door is OPEN. If you can find the wiring diagram easiest thing to do would be to check right from the wires between the door and cab inside the rubber bendy sleeve. See that you can get 12+ first of all and then see if you have ground while open.

I'll give that a shot, thanks. It's weird because the door ajar light goes off and the chime doesn't go off when the key is in and door is physically closed.

Further Googling has me thinking the issue may involve the battery saver relay or GEM...

 

[Bgunner]

Sounds to me like the switch in the door has either gone bad or has become gummed up. Give Dirtmans suggestion a try but I Think you will end up pulling the door panel in the end and testing the switch. If I am not mistaken your dome light/door ajar switch should be located at the latch inside the door and why spraying with some lubed helped it for a short time.

 

[Uncle Gump]

I dont know how the supercabs work, I assume they still only rely on the main door latches for sensors. If they do they are 12 volt constant and get grounded when the door is OPEN. If you can find the wiring diagram easiest thing to do would be to check right from the wires between the door and cab inside the rubber bendy sleeve. See that you can get 12+ first of all and then see if you have ground while open.

These door switches receive a constant 12 volts. So with the door closed (switch open) one wire will have 12 volts and the other wire will have ground (through the bulb). When the door opens (switch closes) and both wires will have 12 volts.

Jim_Philly... you may be onto something with the GEM.