In line brake light switch

I have a question, I just installed a new wiring harness on my 29 everything works just fine except for the brake lights. Everytime I connect the wires to the In-Line pressure switch it trips a fuse WTF am I doing wrong please help.

 

I would put in a new fuse then touch the wires togather if the lights come on then the switch is grounded.if it still blows the fuse you have a wireing issue.I bet it is the switch though.

 

You can check for a bad switch by checking continuity between a wire lug and the base of the switch. Should be no continuity between them.