I just added a sprayer to mine. The spray is activated by twisting the wiper knob. Pull the knob out of the dash and disconnect it. Clean it up and then test continuity by connecting the spray tab and ground on the body of the switch. Twist and the contact should show infinite continuity. If not clean up the contacts on the outside of the switch. Then check the continuity to the 2 wire connector in the engine bay. Mine is on the drivers side near the firewall. If all is good, plug it all back in and you should hear the sprayer motor run when you twist the knob.
Others here have more experience with the motor and linkage. I got lucky and was able to lube everything in place. For the motor I removed the worm drive cover and carved out the crappy old grease, cleaned up the contacts and added fresh new grease. I ran them for a bit and added a bit more and closed it up.