Air problem

[Hulk5T]

Went for my Friday drive and noticed air pressure on both tanks were pegged at 150 ,ran fine but had no air to horn,wipers,or front drive and I noticed it was not popping off at dryer.any suggestions where to start diagnosis? Update , Changed out pressure valve ,now it is releasing pressure and front engages and wipers are working again but now the horn does not work ,any suggestions

 

[charlesmann]

Are you getting power to/from horn button, to horn air solenoid? Are you getting air to the inlet side of the solenoid?

 

[Hulk5T]

Are you getting power to/from horn button, to horn air solenoid? Are you getting air to the inlet side of the solenoid?

It's working again now ,I think it is dirty under the button so will take it apart and clean it. For now it's good and I'm going take it for inspection.thanks for you help.