12v air compressor

[fordboi415]

I have a 12v air compressor from grover industries co. For my air horn. I hooked it up correctly and it won't pump more than maybe 10-15 psi I checked the valves on top of the head and they are good to go so I don't understand why it just keeps running and won't fill my 1gal tank, any ideas

 

[doorgunner]

Do ya hear air escaping anywhere? Also, maybe try capping the pressure line with a air gage to see if it's putting out pressure.