How to Diagnose Broken Bilge Float Switch

[nickfox45]

Time to confess some ignorance - I have very little idea how my bilge pump works! Earlier this season, I periodically heard the bilge pump kick on like it's supposed to. Then I noticed it stopped doing that, and I'm not sure why.

I investigated and found a Rule 1500 bilge pump (which I've learned are not automatic) and some kind of sensor, which I assume is a float switch? When I flick the auto/manual switch for the bilge on my electrical panel, the pump works great, so I'm left thinking it's a sensor/wiring issue.

To excuse my ignorance, I at least attached some pictures! They show the current wiring from the bilge pump to the sensor and my best shot of the brand/name of the sensor. The dark-ish picture shows where those wires lead off to (of course, a part of the boat I'm not sure how to reach!).

I'd really appreciate some next steps or being pointed in the right direction on how to attack this problem. Thanks!

[Rex Delay]

Do not recognise your switch but from my experience, they last about 2 years max. Chuck it and get a new one.

[rwidman]

Originally Posted by Rex Delay

Do not recognise your switch but from my experience, they last about 2 years max. Chuck it and get a new one.

My boat has two float switches and they are original. That makes them 18 years old. I don't think age has much to do with the life of a float switch.

The best way to test a float switch is to use a garden hose and run water into the bilge. At 3" to 5" the switch should turn the pump on and empty the bilge down to about 1/2". Then the pump should shut off.

If the pump does not come on, check to see if the switch is getting power.

[Kelkara]

The Ultra switches are supposed to have a good reputation for durability.
If it doesn't work when you chuck a bucket of water over it, then start by checking the electrical connections ... this might help:
TEF-GEL - Ultra safety systems - Home page

[nickfox45]

Thanks for the link, that diagram looks really helpful. Time to go study...

[bsurvey]

cut the wires and ohm the switch by activating it

[Sailingveterinarian]

Just bypass it..check that there is 12 volts...hook it directly to the bilge pump and see if the bilge pump works.

[Cadence]

Originally Posted by Sailingveterinarian

Just bypass it..check that there is 12 volts...hook it directly to the bilge pump and see if the bilge pump works.

He has done that by throwing the switch to manual.

[Shrew]

The pump has 2 positive leads and a common ground. One positive lead is to the float/sensor switch. The other lead is to the manual bilge pump switch on a panel or a dash. By throwing the manual switch on the dash, you do verify the pump works along with that positive lead and ground connection directly to the pump.

This would mean the problem is in the float/sensor switch, not the pump.

1) Check the positive lead from the bilge pump to the float/sensor switch.

2) Check the positive lead to the float/sensor switch.

3) Check the ground to the float/sensor switch.

Are you getting 12v TO the switch? Are you getting 12v OUT of the switch? are you getting 12v TO the pump? start at one end and work to the other.

[thomm225]

Originally Posted by rwidman

My boat has two float switches and they are original. That makes them 18 years old. I don't think age has much to do with the life of a float switch.

The best way to test a float switch is to use a garden hose and run water into the bilge. At 3" to 5" the switch should turn the pump on and empty the bilge down to about 1/2". Then the pump should shut off.

If the pump does not come on, check to see if the switch is getting power.

My float switch is at least 12 years old. (bit probably 20 or more)

To test it, I just take a long stick and lift the float until the bilge pump comes on! Mine is similar to this but much older:

https://www.google.com/search?biw=12...WME2VsgDo8NFM:

[CarlF]

+1 on water depth. Are you sure the water was deep enough? Those Ultra switches don't turn
on until the water is about 2" deep. You can't lift the float in the Ultra switches as it's in a plastic tube.

Those Ultra switches are great switches. Unlike the Rule switches they last for many years. I've never seen it, but it's possible for weed to grow inside the little plastic tube and keep the float from going up and down. Try putting 3" inches of water in the bilge.
If the pump doesn't turn on after 10 seconds or so, tap the switch gently with a screwdriver handle to see if the float pops free. If the float is dirty, remove it and clean it.

Otherwise, you'll have to get out a multimeter and check the wiring as suggested above.

[Dave22q]

Step 1 confirm it's not a pump issue by turning on manually with the breaker. 2 If pump is working, turn the breaker off, reach into the bilge and lift the float. If pump does not start you have an electric problem or a switch problem. 3 Cut the switch wires and check for current. If current good replace the switch. If not you have to check for a broken wire or loose connection, not fun!

[Dave22q]

Step 1 confirm it's not a pump issue by turning on manually with the breaker. 2 If pump is working, turn the breaker off, reach into the bilge and lift the float. If pump does not start you have an electric problem or a switch problem. 3 Cut the switch wires and check for current. If current good replace the switch. If not you have to check for a broken wire or loose connection.

[Cadence]

Originally Posted by thomm225

My float switch is at least 12 years old. (bit probably 20 or more)

To test it, I just take a long stick and lift the float until the bilge pump comes on! Mine is similar to this but much older:

https://www.google.com/search?biw=12...WME2VsgDo8NFM:

Most float switch are mercury switches which are reliable, no moving parts on the switch just the float pivot. I'd bet on an corroded wiring connection. However, that switch has to have internal connection to the base. At the cost I'd just replace the whole thing. Figure it out and then put it back as a backup pump with the switch higher in the bilge. JMHO

[nickfox45]

Thanks to everyone for the replies. I'm going to start by cleaning the switch, which is probably long overdue, and if that doesn't fix things, then proceed with testing wiring to ensure I'm getting 12v IN and OUT of the switch as suggested.