Seems to me that if the only thing you switched was the switch, and suddenly everything's not working, that's what I'd suspect. I'd swap out the old switch and see what happens.
"Natalie", '66 Coupe, aka "Jinx", "Jinxie Natalie" (everything goes wrong..)
289, Holley Carb, Edelbrock Intake/Water Pump, Northern Rad
3.55 with Posi, Zoom Clutch
Next On the Agenda:
Interior - Soundproof, new carpet, tilt column (done), seat extenders, Motolita MK3 (done)
Exterior/Body/Performance:T5 (done) weatherstripping, power steering (done)