I have been unable to locate a complete wiring diagram for my 1980 K5, so please help.

The parking brake indicator light on the dash is always on.
Brakes seem to work just fine.

I have located the parking brake switch and unplugged the connector. Light is still on.

What else activates this indicator?

I assume that this indicator is activated by completing a ground circuit.

ALSO, if anyone knows where I can find a complete wring diagram for future reference, please let me know.
Incomplete diagrams are easy to find (AUTOZONE).

Thanks in advance.

 

It definitely sounds like you have a wire that has shorted to ground, completing the circuit for the brake light.

As far as a complete wiring diagram, try eBay (CLICK HERE). I found all of the manuals (service, overhaul, and wiring) there for reasonable $$.