Tapping into dome light wiring

[*Als50*]

Here's my question. I want to use the rearview lighted mirror from my long gone '88 fox. Since that harness came with 3 wires, which wire or wires do I take into from my Rangers dome wiring? Thanks!

 

[RonD]

My wiring diagram shows the Light Green/orange stripe wire at the dome light has power all the time, well not "all" the time, it is on the Battery Saver Relay circuit, so GEM will cut power to it after 20-30 minutes of key off/doors closed
This wire is for the "Map Lights", local manual switch for each

The Black/light blue stripe wire only has power when interior light switch is on or when GEM activates Interior Light Relay when doors are opened

Bulbs are Grounded locally, don't show a ground wire

Fuse 26, 10amp, in cab fuse box powers both wires, just in case

 

[*Als50*]

Thank upu, Buddy!