Wiring a backup switch to a bilge pump

As I understand it, the most common fail-point on a bilge pumping arrangement is the switch, and not the pump itself.

So how would I wire a second, higher, float switch, to the same pump? Installing a second thru-hull is not possible in this particular location.

Thanks in advance!

one pump one thtough hull.

just wire the switch in paralell.

Just wire in second switch to pump at connections of existing switch. Locate new switch a little higher if you want to.

We have a second switch in each bilge about 2” higher than the one on the pump. The second switch is wired to an alarm only. I have the pumps wired to separate leds in the pilot house. When the pumps goes the light goes on. If it stays on I need to take a look. If there’s a major egress of water, the second switch tells me pretty quickly with the audible alarm. It sounds complicated but it’s pretty simple.

Thanks guys..... I'd been scratching my head about where and how to put a second thru-hull, and, as usual, the answer was a simple one. Cheers.

Or just pony up and buy a really really good switch to begin with.

caltexflanc said:

Or just pony up and buy a really really good switch to begin with.

Click to expand...

Yeah, I've got Ultra already.....but one of those went bad last year. Nothing's safe.

A second (backup) switch for the bilge pump would be wired in parallel with the first switch. To put it in more simple terms, the two wires from the new switch connect to the same place as the wires from the first switch.

Test everything with water when you're finished to make sure you've done this correctly.

Are Backup switches really necessary?

Years ago, when I had a switch failure, the experts(?) at the store recommended I change brands to try to find a switch that would last, as switches were a very common point of failure. I did so, but was unhappy with the results. after a few tries, I was then told (by the same experts) that Rule switches had improved so much that I shouldn't have failures any more. My present set of switches are all Rule switches, all about the same age, 15 to 20 yrs old, all still performing perfectly well. I test them regularly, keep debris out of hte bilge and all is well.