Dome lamps don’t come on with doors open but may work when overhead switch is activated. The door ajar indicator in the instrument cluster still comes on with one or more doors open, the door ajar lamp in the instrument cluster may stay on also.
This is most likely caused by a faulty diode that is taped into the wire harness, out of sight. But don’t worry, it is easy to repair.
Diode: Kia P/N: 9138A-3E000 Cost: $16.00-$20.00
Located in left kick panel, inside wire harness.
If the door ajar indicator lights when a door is opened, the door switches are working.
To test the diode and overhead switch:
Carefully remove the clear plastic lens in the center overhead dome lamp assembly. You can use a small flat screwdriver in the slot located on the front edge of the lens. Gently release the front side of the lens from the lamp base, then remove the lens.
Now, using a 10mm socket, extension, and ratchet, remove the lamp retaining bolts and remove the lamp assembly from the roof. Leave the wires connected.
If you look closely, you will see that the harness connector at the lamp assembly has the wire cavities numbered.
Locate the red wire in the number one position. Using a 12 volt test light or volt meter, test for voltage at the red wire. The red wire should have voltage at all times.
Now to test the overhead switch and the problematic diode:
Push the (DOOR) button in the overhead switch so the dome lamps work with the doors. You don’t want them in the manual ON or in the OFF position.
Locate the red/black wire in the number three position.
With your test light, check the red/black wire as follows;
All doors closed: Test light should should be on and dome lamps off.
One or more doors open: Test lamp should be off and dome lamps on.
Test results when checking the red/black wire:
In a properly working system, you will have the test lamp act a follows;
Doors open: Test light off
Doors closed: Test light on
In other words:
If test light is OFF with one or more doors open, and dome lamps don’t come on;
Overhead switch is faulty, not very common to see this.
If test light stays ON with one or more doors open, and dome lights are still off;
Diode is faulty, this is by far the most common problem.
Now to locate and replace that diode:
You need to first remove the left sill plate and kick panel trim.
This will expose the cabin mounted fuse box as well as the portion of the wire harness containing the diode that Kia so kindly hid from sight. Don’t worry it is very easy to locate and replace.
You should easily be able to feel the small, hard, rectangular, shape of the diode and it’s socket under the tape with the wire bundle.
This is where you want to very carefully cut open the wire harness covering. Use care not to cut any of the wires or your fingers.
Once the harness cover is cut open, gently peel some of it back and then lift out the diode holder. The holder has two wires going into it, be careful with them and the holder. It is not fragile, just use care and don’t force things.
Now release the little lock tab and pull out the diode from its holder.
Then insert the replacement diode, it can only fit in the socket one way.
Close all the doors to reset the the battery saver mode of the dome lights.
Then open one of the doors. The lights should now work.
Now your dome lights should be working fine. Retape the new diode into the harness to secure it in place.
With everything working reassemble all the interior trim and overhead dome lamp being careful not to pinch and wires.