Door dome light and Door Ajar indicator not working, but left and right individual lights on dome light are working fine on 1999 Ford Ranger XLT Four Door 4x4. Should I check the fuse and how do I do that? Both doors stopped working at the same time and I saw something about a busted fuse possibly being the culprit. What do y'all think?

 

Welcome to the forum

So Map lights work, that's what those left and right lights are called

But no Dome light, these 3 bulbs all use the same fuse, so no not a fuse issue, its fuse 26 in cab fuse box, just FYI

Does the dome light come on when you rotate the Dimmer wheel all the way "up", if so the wiring to dome light is OK

Now the Complicated part
1995-2003 Rangers use a GEM(generic electronic module), its the Body Computer(BCM), it runs ALL the electrics in the cab
i.e. your wiper switch is NOT connected to the Wiper motor, wiper switch is connected to the GEM and GEM is connected to wiper motor
When you turn the wiper switch ON, it tells GEM you want wipers, GEM then closes a relay to turn wiper motor ON

Same for Dome light, the door switches are connected to the GEM, the GEM is connected to the Door Ajar Light in dash and to Interior Light Relay
So when door opens GEM gets that GROUND signal and turns on Door Ajar Light and Interior Light Relay(activating Dome light)

So the door ajar light and dome light only have 1 common link, the GEM

Its not the Interior Light Relay because door ajar lights would still work if this relay didn't
So the GEM is either not getting the GROUND signal from either Door switch, possible, or the GEM circuit for "door open" is bad

Check Fuse 25, 7.5amp, in cab fuse box, its for the GEM and has power all the time which is what is needed for the dome light setup, the other GEM fuses are all key on only power, but if you want to check them its fuses 10, 20 and 28, all 7.5amp

 

Thanks for the welcome. I don't know what dimmer you're talking about. The only dimmer I know of is the one for the dashboard lights. This happened all of a sudden last night when I discovered neither the door ajar indicator would come on with the engine on and the dome might wouldn't come on with or without the engine running. Hiw does one safely get inside the fuse box? I've never done it on my own.

 

Rotate that dimmer all the way "up" and then keep rotating and you will feel a "click" and that turns on the dome light manually, main light switch doesn't need to be on
This also turns on the Cargo Light in the 3rd brake light housing on the top back of the cab


Click on this link: https://www.ranger-forums.com/genera...1-models-3747/

Download your 1999 Owners Manual

Go to page 134 and it tells you how to check fuses and how to open the cab fuse box