The brake lights on my 67 coupe don't work. I checked the brake light switch, and it has good continuity, but no power into it. I traced the wire back to the headlight switch, per the wiring diagrams, and found that there is no power getting to the post. I also checked that there was good continuity between the brake light post and the battery post, but there is power going to the brake lights. Could it be that the headlight switch needs to be replaced, or is my wiring all wrong? I'd rather not order a new headlight switch if there is nothing wrong with the existing one. Does anyone have any advice?

Many thanks!