1972 blazer electrical problems

[JDSurge]

Well, I checked the light switch. When I ohmed it out, I had 12v power to the switch and when I pulled it all the way out (headlights on) it put the power to the terminal for the Blue wire, headlights. When I pulled the switch half way out, running lights, there was no continuity between the 12v power terminal and the 18 brn wire terminal. This looks like to me that the switch is bad. It looks good from the outside but I have had the same switch fall apart that I bought from LMC 2 years ago. Does anyone on here have any experience with how the light switch works? I hate to order another one and not be the problem.
Thanks for any help.
JD