I read all that but I would like more specific information, such as maybe a diagram, and the type of diode I would need. Thank you."If you want your map lights to come on with your dome lights yet work individually as well, it's a bit tricky. You have to change the lights to a switched ground
1. Cut the factory wires where they split (both orange and black). You will want to swap the leads going to the map lights with each other (this will make it so the map lights are switched by ground just as the dome lamp).
2. Then you will run a wire from the dome light ground (which is white at the dome light) to your console.
3. Splice a Diode between each switch and each light, and connect both to the white lead. Be sure to keep the diodes leads separated on the console side going to the map lights. Follow the package directions as a diode only allows current flow through one way.
4. If everything works correctly, both map lights will turn on with the dome lights, and work individually with the button. If you have the diode wired the wrong way the switches will turn the dome light on but the dome light won't turn the map lights on. "
Just about any 12v diode works, i typically buy this package as they work for everything i've ever needed. https://www.radioshack.com/products/rectifier-diodes?variant=20332040133
As the instructions say, swap power and ground near the plug (two wires). Run the dome light switched ground (one wire) to the console. At this point, you will want to splice the diode into the the wire that runs between each map light and the switch (2 splices, 1 at each light) and connect that to the dome light wiring.
All said and done, the bulbs in the map lights will have constant power running to them, and the switch will now control the ground. The diode protects the ground from backfeeding into the dome light, but allows the dome light ground to turn the map lights on.
Sorry I don't have something more specific for you, and i don't have time to create a wiring diagram right now.
you splice the diode into the wire that runs between the map light and the switch, and connect it to the wire you run to the existing dome light.