Greetings!
I searched the forums pretty extensively but did not find anything related to aftermarket keyless/central door locking systems, only issues with OE power door locks and adding keyless.
This past weekend I installed a central door locking system with a Scytek G20 "alarm" as the keyles entry module along with power mirrors (OE parts) and power windows (Electric-Life bolt-in kit). I am not using any alarm features other than parking light flash (onboard relay) and dome light supervision so the dome will come on when the truck is unlocked.
The install went well and everything works, however, I did not test drive the truck (my daughter's ride). She left for school this morning and sent me a text saying the door ajar light on the dash kept coming on along with the chime. I asked her if the dome light was coming on too and she said it wasn't, so I'm fairly certain it isn't the door trigger switches at the door latches. I did unbolt the latches to install the door lock actuators though, so I might have to pull the door panels and double check their connections.
But I want to rule out it is something with the dome light supervisin circuit. On the Scytek it is a BK/W - trigger 500ma output. The Ranger's dome light wire is Y/BK at the GEM, which I later found out is also the driver's door trigger. I wired the BK/W wire to the Y/BK at the GEM using a standard Bosch 30A relay wired for negative dome light trigger as such: BK/W to pin 85, +12V to pin 86, Ground to pin 30, and Y/BK to pin 87. Like I said it works fine when tested in the driveway. I saw in some diagrams a diode was used to isolate door triggers, but I'm not using the alarm's door trigger wires at all, just the dome light wire via a relay. Would that still need a diode? I'm thinking not because the relay is open when the truck is running down the road.
Thanks in advance to all who reply!
I am betting on a pinched wire. Use a meter to see which door is causing the problem, remove the door panel of that door and make sure there is not a wire under the mounting bracket of the new window tracks.
Thanks for the reply. The window kit is a direct-fit bolt-in setup that uses the existing holes in the inner door sheetmetal. The regulators were bolted in before ANY wiring was done, so there's no chance a wire got between the regulator mounting and the door sheetmetal.
I'm pretty sure it is one of two issues, the door latch switches (a fairly common Ford problem, but one the truck has not had until now) or the connection to the dome light/left door trigger for the dome light supervision wire from the keyless entry/alarm module.
Thanks...
You have probably gone through this step already, but it may help someone else searching this for a similar problem. The next step would be to disconnect the dome light supervision wire from the door trigger, and then test drive the vehicle. Is the issue fixed? If yes then the issue is in that circuit. If not fixed your problem is a loose connection or other issue elsewhere. Think about the problem as a flow chart and start ruling out (by TESTING!) everything that you touched in the vehicle. Not saying YOU did anything, but sometimes by just working on a car we can make existing problems, that may have been hidden, become apparent. 
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To master and control electricity is perfection. *evil laugh*
That would indeed be my next step. However, more research shows the door switches to be a fairly chronic problem with the Ford Ranger, Explorer, Expedition, etc. The fix can sometimes be as easy as dousing the latch mechanisms with WD-40 or similar product. I did that last night and verified the rear cargo doors were fully latched as well. Test drove the truck and no door ajar light. My daughter drove the truck to clas today and said the light did not come on to/from school or to work, so I'm fairly certain in this case it is the OE Ford latch switches possibly acting up (or the rear doors not closed right). Anyway, for now things seem to be fine. If the door ajar light comes back I'll continue my diagnostics.
Thanks all that posted suggestions/ideas.
The same thing happened to my explorer twice in the 8 years I had it. I sprayed the heck out of the latch with wd-40 and worked the door latch by open & closing the door. Doing that solved the problem both times. The latch is very problematic on those cars as you said.