I searched and found a few threads related to this problem I'm having, but they mostly stopped with "pinched/crimped wires".

So, my "door ajar" alarm stays on and the dome light stays on until the battery save feature shuts it off. Once it is shut down, I can open and close 3 of the 4 doors and the light comes on and goes off. However, when I open/close the left rear (passenger/rear) door, the light doesn't come on.

It's the left rear door, right? Wrong. I replaced the latch which has the integral switch and it still does the same thing.

So I traced the door ajar switches to the C1 connector at the instrument cluster .........

Pin 18, wire G75, color TN, driver door
Pin 19, wire G77, color VT/OR, driver rear door
Pin 20, wire G76, color TN/YL, passenger rear door
Pin 21, wire G74, color TN/RD, passenger door

When a door is open, the door ajar switch takes the circuit to ground. Using my DVM, I confirmed that all 4 door ajar switches and related circuits are performing properly from the door to the cluster.

From there, I lose the circuit. I see no evidence that the circuit makes it to the FCM or PDC (ICM). There are several B+ pins on the cluster, so I assume one of these is where the circuit is charged.

My dealer confirmed that this circuit should stop at the cluster, but said he could scan it Monday. In hopes of canceling my trip to the dealer on Monday, and leaving for California before then, do any of you have any suggestions on where to look next?

 

This is a common problem with Ford Rangers. I know this is a simple question, but did you spray WD40 into the latch on the door? I had the same problem with a ranger truck and it was just a dirty contact in the door. I sprayed it and open and shut the door a few times then repeated 3-4 times. Lights all go off now. Might give it a try.

 

Thanks, yeah, a sticky switch could certainly act like a bad switch, but the meter showed the switch to be working properly.

 

I'll just let the dealer look at it Monday I guess. I'm neither a mechanic or an electrician and I've gone as far as my feeble brain will let me

 

i had this problem , wires were good , fuses good , latch worked . Tried everything and light would not go off .
I then realized the door handle is a sensor . I looked under it and there was a small amount of dirt .
I dusted off the dirt and low and behold the light went off and everything worked fine .
Just that tiny amount of dirt blocked the sensor and signaled door was not completely closed .
How simple ! This saved me thousands of dollars! Because if taken to a shop they would have torn the door down. And likely it still would not have fixed the problem unless the dirt fell off .
Hope this helps