edit
n’mind, found it
I don’t want to start a new topic, but I have a big truck horn, and my dad is looking for a compressor that will hold air, is electric, and run off the battery. He wants to mount it to his truck. Does anyone have one cheap?
I think you could use a small tank and probably any air horn pump with a check valve installed between the tank and pump. IYou would also want some kind of a pressure switch to shut the pump off and a pressure relief valve.
The main problem with the pumps that come with the air horn kits is they don’t put out quite enough pressure so the horns are not as loud as they could be.