Fix For Inop Washdown Pump

[CaspersCruiser]

Here's some knowledge that may help others avoid an expensive misdiagnosis.

My new-to-me 2012 R27 was delivered with an inoperative washdown pump. The previous owner indicated he thought the issue was a faulty ON/OFF switch. I checked the switch with a meter and it operated normally. While checking the wiring for the switch and the adjacent fuse, a wire carrying 12VDC to the fuse broke at a butt splice located eight inches from the fuse down inside a section of black split flex tubing. That took a few minutes to uncover.

The cause of the wire break was severe corrosion. The butt splice was good quality with a heat shrink insulator, but inexplicably, the insulator was not shrunk to seal the connection thus allowing the corrosion to occur. I fixed that problem, but this time used a heat gun to shrink the insulator to seal the connection.

I reconnected all the wiring and switched the pump to ON, fully expecting the pump to operate, but no joy. Twelve volts DC was coming through the fuse to the switch and out to the pump's power lead, but the pump wasn't running. I began to suspect the pump, but just couldn't imagine how a good quality seldom-used pump would fail. I checked for continuity through the pump wiring and it checked OK.

I turned my attention back to the switch and fuse. I repeatedly checked the switch and each time it operated normally. I then checked the fuse assembly and noted that continuity seemed to be intermittent and resistance high, although readings like I was getting can sometimes be caused by poor metering technique. Then it dawned on me that the washdown pump needs a lot of current to operate and, even though 12VDC was getting through the fuse and switch, the current supplied may not have been enough for the pump to operate. The pump fuse is 20 amps, which is a lot for 12VDC.

Today, I bought a good-quality marine fuse assembly and 20 amp fuse and installed it. It was a 10-minute job. I switched the pump ON and heard the sweet sound of a strong-running washdown pump.

So the lesson learned: If your washdown pump stops operating, check that fuse assembly! I spent a lot of time figuring out that one.

 

[stwendl]

Interesting, my 2015/16 washdown and macerator pump had also a non applied heat shrink connection in the engine compartment. But all is working fine. It's a bit hard to apply heat to that area down there unless you use a heat gun with a bent shield which allows the hot air to go around the cable connector and not hit the walls. I am sure the factory will add this to their list of checkpoints.

 

[knotflying]

That entire switch assembly is in a bad spot. Water flying into the cockpit always hits that spot. Keeping things corrosion free on the switch and fuse assembly is one of my preventive maintenance jobs. I also noticed that there was no backing gasket on the assembly back. I installed one and that has helped to prevent water from infiltrating in and then running onto the connectors.

 

[captstu]

I had the opposite problem - the washdown pump was frequently running - even when no one was in the cockpit. Maybe you had the same problem?

If one fuse is good, two are better?

When mine failed, I found a second fuse labeled W.D.Pump, near the batteries. The fuse had corroded in the connector.

I removed the fuse in the cockpit, respliced the connectors, and replaced the fuse at the batteries - sure enough, the W.D. pump had a mind of it own and started switching itself on randomly - i now know that a coiled dock line hit the switch when a wake hit the boat.

Since I don't use the W.D. pup (my boat is dry stacked and fresh water washed), I removed the W.D. pump fuse in the battery compartment and labeled it as off.