There is not much that can go wrong so check your work and eliminate every step one at a time.
It is important to have a multimeter that can read volts and ohms. If you haven't got one, go buy one now!
Starting at the light unit, set the multimeter to read volts and connect the black lead to a good earth point (such as the metal cigar lighter casing) and the red lead to your new wire.
Switch on your sidelights and check that the multimeter reads 12v (or close to it).
If it does, the problem is with your new light unit.
If it does not, the problem is with your wiring.
I notice like most people you use scotchloks. I am not a fan of these. They were originally designed to be used as a temporary connector for the telecoms industry and despite what many people beleive are not suitable for automotive applications - especially where high currents are involved as they have been known to cause fires.
There are safer alternatives such as the Posi-tap or T-Tap.