In this example of how to install a washdown pump I will be replacing a below deck raw water pump on a 25-foot Grady White center console. The only symptom supplied by the operator was, “The system popped the circuit breaker when I tried to use it”.
With these symptoms I suspected a locked-up pump. The first thing I did to troubleshoot the system was go to the pump and measure the input voltage. To do this I had to remove a deck panel and then pull apart a wire harness connector near the pump.
The pressure hose, seen on the left, is secured with padded stainless steel cable clamps. The pump has its own pressure switch to turn it on when demand is sensed. It is mounted to the vertical bulkhead with shock absorbing bushings.
Voltage here was good, just a couple tenths of a volt below battery voltage.
With this noted and the pump looking pretty corroded it was obvious the pump needed replacement.
Of course, on a boat when you start to take things apart other issues become readily apparent. Our how to install a washdown pump tutorial would not be complete with mentioning this reality.
In this case the issues noted were minor, the area needed a general cleaning and a few wires needed to be re-secured to the bulkhead.
I selected an Aqua Jet WD 3.5 as the replacement unit on this installation. On my 25-foot Contender where a little more flow was desired I have an Aqua Jet WD 5.2 installed on a freshwater washdown system. Several years ago I reviewed these two pumps as well as a number of others for a well-know