Im having an issue with my domelight remaining ON with the key in the OFF position, this is also affecting my security system, because when I arm my vehicle, it reports back to me that it has armed but a door is open. I'm able to arm my system and reach through the window and open the door and it will not cause the alarm to go off which is my main concern

Now if I have my key in the ON position, opening and closing any door will cause the domelight to turn on and shut off as it should. And if I arm my vehicle while the key is in the on position, it reports back that it was armed successfully without issues. And if I open a door while it's armed and key is on, it will trigger the alarm like it should.

This is also making it so I'm unable to program my security system to change features since it requires a process of opening a door and turning key on and off.

I've read other forums that say to spray wd40 in the door jam, and I've even cleaned out the connectors but it doesn't seem like that's the issue since it works normally when my key is on. And it's always been like this, even before I had installed an aftermarket alarm system.

 

What Year Ranger?

2 door or 4 door?

GEM module 1995 to 2003 operates the Dome light and door switches

Yes, the door switches are located at the bottom of the latch in the door, so and dirt and debris with water washes down and into these switches, causing then to stick
Door switch is OPEN when door is Closed, and Closed when door is open, its a Ground switch, so when GEM see a Ground on that doors wire it activates dome light and "door ajar" light

Unplugging a switch leaves it in the OPEN position, so no door trigger, you can remove door panel and unplug the switch, just to see if thats the problem, and all door switch should be checked

You have to remove the latch to change the switch, as it is a twist lock and can't be turned with latch bolted to the door.

 

It's a 95 ranger 2 door

And I don't have an issue with the door ajar light being on, that works like it should.

So is the issue my gem module?

 

Bump

 

So door ajar light works with either door being opened one at a time, light comes on and then goes off when door is closed

If so then not a GEM issue

Dome light should be powered by fuse #27 in cab fuse box, pull it out to confirm, it should have power key off but only for 30 minutes or so after key off, as it gets power from Battery Saver relay

There is a dome light relay just above gas pedal area in Relay Box 1

There are TWO ways to activate dome light

12volts from fuse 27 runs to the Dimmer Module, dims dash lights, and when turned all the way UP it activates dome light, thru the Relay when its OPEN, 5 pin relay

12v from fuse 27 also runs directly to this relay, this allows GEM to activate the relay when a door is opened, GEM closes relay to send that 12v to dome light


Your issue seems to be a door switch not dome light, since dome light has no connection to alarm, its just activated with door OPEN like the alarm, so..........................it is a door switch issue or alarm wiring issue causing GEM to think door is open