2005 peterbilt 379 brake light switch location

Where is the brake light switch on 2005 379? Normally there is a manifold under clutch pedal but there is not one on this truck. The problem I have is there is brake lights on cab but not on trailer. The customer has a electric brake added into the truck (predator DX2) and not getting signal there either. Any ideas?

 

I will look in the morning. My dad removed the panel and said nothing was there. I don't see anything in there just looking through the hole where fuse panel is located(big hole). At least not where I normally see them. If it is there I am going to choke my dad.... J/k

 

Thanks. I called two Peterbilt dealers and several other shops and no one had any idea where it was.

 

Is there a separate switch for cab brake lights and one for trailer brake lights?

 

Found the switch and it was working like it should but was not transferring power to outside at junction. The wire number on the switch matched the number on the junction block. Does that wire (279) run into anything between the switch and the junction block?