1966 Catalina Blower Switch Wiring

Hello. I'm trying to troubleshoot why my non-AC blower is not working while using the switch. I put a 12 volt source directly to the blower and it worked. I changed the resistor and still nothing. I then put a 12 volt source to each fan speed prong (red, black, black/orange) picture attached, on the harness and the fan worked on each prong. I believe the problem resides in the brown wire that provides power to the switch. I put a voltmeter on the brown wire and it gave a reading much less than 12v. Is this wire supposed to produce 12v?  I put a 12v source where the brown wire plugs to the switch and the switch worked. I tried to trace the brown wire but it's wrapped in a loom that heads near the instrument panel. Any suggestions or guidance is greatly appreciated.