so in short you are by passing the wires in the ignition switch & wiring the solenoid to a switch & it works?
Check the fuses?
I would one check to see if it is in my ignition switch if not then check to see if something has been fucked with in the harness.
from what I gathered is that all u did was bypass the ignition switch & it works. so either the 1 switch isnt working 2 switch isnt getting proper power 3 fuse 4 wires fucked up somewhere.

I think i said the same thing 2 times...