I don't know your coach specifics, but if the water pump fuse is good and you have proven the pump motor is good, it is possible that you have a pump control relay that is not working, or simply a bad connection somewhere in the control wiring for the pump. If equipped with a control relay (which I would bet), the trick will be finding it. In my 2013 ACE for example, the water pump control relay is located under the bed. So basically when you turn on the pump switch it operates the pump control relay and power is fed to the pump motor. This allows the use of a cheap switch to power a higher amperage pump motor. It could also be the pump switch or a loose wire on that too.
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