Outside Shower

[CKinsella]

I have a 2004 Jayco class C motorhome with an outside shower, nice feature. I had used it to wash my hands after dumping tanks, it was good to have.
I replaced the indoor shower with a new stainless hose with a larger shower head. I decided to take the old house and shower head to the outdoor shower. When I hooked it up and turned it on water started shooting out of a small 1/8" hole in the top of the fixture. With the house hooked up no water comes out of the shower. It all comes out of the pin hole.
The hole looks like it's original, made in manufacturing but I can't figure out why I have av outside faucet instead of an outside shower.

[Heady]

Many shower heads have an on/off on the head itself, any chance the switch was accidentally switched during the install?

[CKinsella]

I think that I tried it both ways, but there is still that 1/8"hole that I can't account for.

[RedHorse1]

That may be a hole for an anti siphon valve. Sounds like something is backwards.