I have a water flow problem I could use a bit of help Lads and Lasses. 1991 Hymer B564 My shower has stopped working, I think it may be a pump issue but need some help diagnosing where the fault lies. When I opened the access point the pump appeared to be coming apart, separating at the top end where the outlet feed to shower hose exits. i don't know the make of tap/switch but photo below. I pushed this back as far as it would go without too much force, the shower then pumped on its own, long enough to get me wet then stopped. I have checked the switch, it has 13.6v going to it, I can hear the microswitch work, I have cleaned the spade connectors. If I turn on the sink tap and open the shower tap the shower will then work, and I can alter the water temp by the shower switch and even stop the flow by turning off the shower tap, but once I turn off the sink tap the shower stops flowing. Can't be an airlock but not sure where to go next, I don't want to spend money on a switch or pump I don't need, and I do like my shower each morning. Any help would be appreciated, thanks in advance. Hymie.