How to get air to trailer handshank hookeup

[M1028A1ShelterCarrier]

This could be a dumb question but I have hooked up my airhose to the handshake valve. Then Ive opened the valve next to the hankshake and nothing. I even got under the truck and followed to the line back the tank area looking for anothe valve. An I missing somthing? It there a hidden valve or switch?

Thanks for you help in advance.

 

[Wild Horse Hans]

The gladhand on the drivers side only sends air when the brake pedal is pressed. The one on the passanger side sends air when the manual valve is opened.

 

[M1028A1ShelterCarrier]

I knew it would be somthing simple like that. Thanks for your help

 

[tm america]

love the avatar