I need to find the location of the 4WD. indicator light switch on my 1975 Chevrolet pickup.?

I have a 1975, Chevy 1/2 ton, 4 WD truck, with a new process 203 transfer case. I can't seem to locate the 4WD indicator light switch on the transfer case, it is NOT on the shifter as some are, any help would be greatly appreciated.