Winterizing shower problem

Sprocket

We are winterizing our tab 320 2022.  Everything has gone great, but we can’t get any antifreeze through the external shower.  I removed the shower hose @nd held a can there.  Still nothing.  All other ( sink and inside shower) went fine.  Of additional note, the pump never seems to turn off like it does in dry camp mode. 

Sprocket

One more thing to add.  The kitchen sink worked great, and the shower worked great, but when I try to use the shower sprayer into the sink I don’t seem to have enough pressure.  It just spits   I can of course pour some AF into the trap, but I am now wondering if there isn’t enough pressure to get the AF to the external shower.    

Sprocket

The problem was that the pump lost its prime.  I found the solution here. https://tab-rv.vanillacommunity.com/discussion/16292/2021-tab-320-pump-runs-wont-suck-thru-sanitize-port#latest