Dome Operation

Can anyone explain the sequence of operation, of the dome light circuit. Do doors have a switch somewhwere, or is it an optical sensor of some type? What part of the door contains the switch, is it built into the latch, as i was told? Darn if i can find it. 2001, dodge neon. 4- door. here switchy switchy!!

Yes it is built into the latch. If you have electric locks; the lock motor is built into the latch also. When the door is closed it sends a ground signal to the cluster. Dome light is powered up at all times and cluster grounds the light to turn it on.