There is no fuse.
With the ignition on, does the dome light turn on in one of the 3 positions? Do the power mirrors work?
Pull the dome light to verify that it's connected, but it sounds like you have an immobilizer issue.
The dome light and door lights get a constant 12V+ from the immobilizer "consumer switched off" circuit (also powers the power mirrors, which is why I asked if they work). When the dome light is switched to the "on" position, it gets a solid chassis ground. In the "on with door open" position, it gets a switched ground from the immobilizer "inside light" circuit.
You can use this information to test the connector at the dome light, but since it has a constant ground in the "on" position and you aren't getting any light in that position, it would seem that the "consumer switched off" circuit in the immobilizer is not providing the constant 12V+. Check the mirrors.
Your caps button seems to be sticking...
