I kind of enjoy wiring after cleaning up the mess left by the PO of my car.
Mine is a 68, so my wiring is different, but use this diagram for a 66. http://hammar.dyndns.org/~djhamma/wi...6/66inter1.jpg
The blue-red looks to be #19, which is indeed the instrument panel lights.
The diagram shows it going from the light switch to the fuse box, then to the instrument panel lights.
The black-blue is wire #53, courtesy lights.
The diagram has it going from the light switch to left and right courtesy lights.
The yellow connector looks to be green/yellow #54, to console compartment light.
Can't quite make out the blue connector colors, but it probably is black/blue #53, to console courtesy lights.
It looks like wire #25 (black/orange) supplies power to the light switch
I'm thinking that red connector is #490. transmission selector indicator, on the accessory page.
So to answer that question, no, do not connect courtesy lights to it. http://hammar.dyndns.org/~djhamma/wi...6/66acces1.jpg
Check that you're getting power from your light switch.
Is it turned off? (all the way to the left).
Maybe you have a bad switch.