I would strongly encourage you (& everyone) to add a separate relay to drive the water pump. I too finally converted to Aquajet after experiencing 3 - dead Shurflo failures (a 4th one leaked). However, in the process of troubleshooting a Shurflo problem I discovered that WRV used relatively small wire to connect the 3-way switches (like 22 AWG!). These pumps are rated for 10 amp operation and using that small of wire can cause considerable voltage drop especially when considering the wire distance from the switch to the pump. One owner reported that he measured 10 - 10.5 VDC on the pump with the original wiring.
The Aquajet manual specifically states that a separate relay be used to power their 10-amp pump. I share relay power with the power reel source in the service compartment using a SPDT toggle switch to select pump vs. reel which guarantees that the associated fuse doesn't blow. The toggle switch is not required but you'll need to make sure you don't use the reel while the pump is running.
Does the original wiring work? Of course it does! But what is that voltage drop doing to the electrical integrity of the pump. Sorry but 3 - pumps going dead convinced me that another problem existed. Wrong gauge wire! That's my story and I'm sticking to it!