I'm taking my Cougar throttle apart again, and I notice there is a yellow wire that is screwed on to the PCB. The last time I opened this throttle up, I forgot where it was attached to so I just screwed it on to one of the bolts in the throttle assembly. Any ideas where it really should be attached?

I don have that one, but IIRC it was there to earth the throttle handle to the base. Any screw on the PCB will connect it to the metal of the base, I think.

Check here -Ice

http://www.cougar.flyfoxy.com/circuits.php

Nope, it's not on the diagram...