I think there should be a fibre optic cable to that switch. It's a little less than 1/8" diameter with a brass end. It fits into a small hole in the back of the switch. They pop out easily, look around the rats nest of wiring and you should see it laying there.

OOOPS.....I didn't notice the year. Probably a totally different switch than I thought too...my bad

__________________
1986 560SL
2002 Toyota Camry
1993 Lexus