dimmer switch replaced but wont work

[73 challenger 440]

I replaced the switch for my dash lights, I noticed there is a blue wire there thats not hooked up, it was like that when I removed the original.. what wires do I test to find out if there's juice?  how do I trouble shoot to solve the dash lights not working, they use to work, then one day they just stopped, so I replaced the switch, but still no lights.

[Chryco Psycho]

have you checked the floor dimmer switch

[Bullitt-]

Looking at a 73 Dodge Service manual, It appears the incoming power is a black wire coming from the headlight switch to the LH (drivers side) terminal. RH terminal appears to be for dome lamp. Middle terminal is identified as E1-18T (no idea what color T represents) heads off to harness I guess to connect to cluster lamp wires which are Orange.
I looked up thru the dark abyss of my dash and it appears this center wire is DARK Blue. You should be able to ohm out to the lamps orange wire.   

[73 challenger 440]

well, I had to run a jumper wire from the middle connection to one of the wires on the end of the connector. now they work they just dont dim..