Please Help Troubleshoot My Bilge Pump

[apweng]

Hello,

I am seeking guidance on troubleshooting my bilge pump (Johnson with Manual/Off/Auto rocker switch - pictures in attachment).

The bilge pump was working fine until I removed the fuse panels to install a battery monitor. To simplify the battery monitor installation, I disconnected all the wires to the back of the bilge pump rocker switch. I took a picture of the wiring before doing so.

After successfully installing the battery monitor, I reconnected the wires to the bilge pump rocker switch as per my photo, and the light on the bilge pump rocker switch came on when the switch was in the off position. When I changed the switch to Manual and Automatic (there was water in the bilge), the pump did not turn on and the switch remained illuminated.

My first thought was that I damaged the bilge pump rocker switch somehow when removing the wires from the back.

I did some continuity tests on the switch (all wires disconnected) and the results are described in the attached PDF. As far as I can tell from these tests, the switch is not damaged. Is this a fair assessment or do I need to do more tests on the switch?

I tested the voltage on the wires coming from the battery to the rocker switch and those are fine. I also connected just the battery leads to the rocker switch (no fuse, float switch or pump connections made to the rocker switch), and the switch illuminated in all 3 positions (Off, Manual, Automatic).

I will next test continuity on the wires to both the float switch and the pump itself but seems strange that the function of the bilge pump would cease after disconnecting the wires in the panel, and not going anywhere near the bilge itself.

I’m wondering if somehow when disconnecting the wires on the rocker switch that I caused a short and damaged the float switch, or the pump itself. Is this within the realm of possibility?

Is testing continuity to float switch and to pump the next logical step? It seems like it would be, but I don’t understand how I could have damaged the float switch and/or pump by disconnecting and reconnecting the wires on the rocker switch. I was careful to reconnect exactly as per my photo.

I will get down to the boat again on the weekend but wanted to be armed with more information before going.

Thanks!

Andy

[Kelkara]

Are you sure the big red wire with the fuse should go between 1 and 2? It would make more sense if it joined 8 and 2.

If I understand what the switch does, there needs to be 12V at pin 2. Since your fuse is not integral to the switch unit, you need to wire pin 2 via the fuse to 12V+.

[APWTryfan]

Originally Posted by Kelkara

Are you sure the big red wire with the fuse should go between 1 and 2? It would make more sense if it joined 8 and 2.

If I understand what the switch does, there needs to be 12V at pin 2. Since your fuse is not integral to the switch unit, you need to wire pin 2 via the fuse to 12V+.

Thanks for that I will double check on the weekend. Hopefully that is the issue! I will respond after checking...

[Kelkara]

ok. I just downloaded the pdf ... the wiring diagram is on page 9 ... pin 8 should be connected to pin 1 and the 12V+ should connect through the fuse to pin 2.

[SV__Grace]

During an 18 month refit of our boat I got to know our electrician really well and helped him and worked alongside him as much as possible to learn as much as I could.

During our work together, every time I struggled with something that didn't work he would remind me of Rule #1: "Always check the power source first."

And darn it, after tracing back to the power source I would always find the problem!

Of course, this assumes the wiring is correct, which should be simple as all devices come with wiring diagrams.

Testing a switch is easy, just remove the wires and put them together and the device should turn on.

Funny story- just last week, here cruising the San Juan Islands 3 years after our refit and 6 months after our electrician upgraded our batteries from AGM to Lithium, I discovered the high water bilge pump wasn't working. With two bilge pumps and their switches it is a rats nest of wires going every which way and the more I rooted around the more confused I got, then I remembered Rule #1 and quickly discovered that my wonderful electrician forgot to connect the high water bilge pump to the batteries after installing the new ones.

[sinnerman]

Terminals 1,2,3 will be the rocker switch with the center terminal (2) being the common.

Terminal 1 (Manual) would be the wire going directly to the pump to turn it on manually.

Terminal 3 (Auto) to the pump float switch.

The middle terminal (2) is the switch common and receives power from the fuse (battery positive).

The bottom two terminals (7,8) are most likely for the indicator lamp.
One terminal is negative and the other terminal gets connected to either 1,2 or 3 depending upon when the light should be illuminated.

(Most likely to terminal (1) to light up whenever the pump is actually running.)

If the light does not come on swap the leads (7<->8). [ LED's are polarity sensitive]

Also, standard practice is to connect the bilge pump directly to the house battery and not through the battery "1/2/ ALL" selector switch. This assures that the bilge pump cannot be inadvertently switched off when leaving the boat.

Cheers