2000 Internataional 9900i Brake lights not working

I'm having issue with my break lights not operating correctly, the blinkers and park lights work, but when the brakes are in use I do not get any break lights, I've traced the wires back to the area on the passengers side of the truck under the hood on the fire wall, not getting power there, not sure where else to look any ideas?

Thanks!

 

Yeah I found that switch connect to the air lines, that switch should close wen the brakes are applyed correct? I by passed it to see if the lights would could on at that time, no luck

 

Alright I'll get dig into that one when I get some day light, thanks for the pointers