Bilge pump won't shut off

[muskyfins]

Yesterday while covering the boat, the Admiral says she hears something running in the engine compartment. Turns out to be the bilge pump. I figure the float switch is stuck and tap the side of it (Rule a matic plus). Nothing happens. Trying to figure out why it won't shut off, I lose my temper an cut the wire from the switch to the pump. Guess what? Still runs. A little more anger management issues and I finally cut the brown wire. Pump stops.

Then I notice the mid-ship pump is also running. Open the hatch and tap float switch to no avail. Still holding the side cutters, so yep, cut that brown wire too.:frusty::frusty:

At that moment it dawns on me that I could have disconnected the battery, but my anger got the best of me. So now I've created work for myself.:facepalm:

Here's the question:

Are the two pumps on the same switch circuit somehow? As some type of fail safe or something? (note they each have their own float switch)

And why when i cut the switch wires didn't the pump stop? (the helm switch was off) Again, is this some type of normally closed switch? Seems far fetched, although that would provide an additional level of fail safe.

Any help is appreciated.

 

[alldodge]

With Rule Brown is main power and Brown/White is manual override. So cutting the Brown would stop all power thru. Depending on how its setup, I would look for a common float switch that's hanging

 

[muskyfins]

I knew the brown was main power, but why was it hot? I had already cut the switch off, so no voltage should have run to the pump. So you're thinking there is a common circuit for the switches? Maybe I cut the wrong switch and the mid-ship switch was hanging?

 

[alldodge]

The Brown wire is always hot (so long as the fuse has not blown), and it goes to a float switch and then to the pump. My thought is you have a common connection between the pumps which is probably a float switch

 

[muskyfins]

​The brown should be dead in the following diagram when I cut the black float switch wire and the dash switch is set to auto. Unless power is coming from soewhere lese per your suggestion. I'll check the second float switch tonight and see if it's fouled somehow.

 

[alldodge]

In your wiring diagram then I agree it should be dead

But if it's wired like that, then how could it stay on? There is a reason it just has not been found yet. The issue is yours is not wired as in your pic

 

[alldodge]

BTW, the pic your showing has NO manual override. If you have a manual override the this is not your diagram

 

[sam am I]

I knew the brown was main power, but why was it hot? I had already cut the switch off, so no voltage should have run to the pump. So you're thinking there is a common circuit for the switches? Maybe I cut the wrong switch and the mid-ship switch was hanging?

I do think/agree its float switch #2 hung, that is if I guess the wiring correctly.............See below,



If SW2 is closed (hung up) and you cut the wire "BLK-1b" feed to pump #1/M1, both pumps should still have been running as you noted due to "BLK-2b" still feeding +12V to "BRN-1" and "BRN-2" via "BLK-2a/Auto".

Like I said, just a guess with the wiring info you presented running with two pumps, two floats and how you explained things occurring.

 

[alldodge]

Agree, if (the big if) it is wired like in the drawing

 

[dingbat]

I've had two bilge pumps short thru the armature by-passing the helm and float switches.

 

[muskyfins]

I believe the wiring diagram in Sam I am's post above is correct.

Went down to the boat last night to confirm a few things. (now with a cooler head ) I temporarily spliced the brown power wire back on the cabin pump which caused it turn on. While it was running I was able to work the float itself (still in the cabin hatch) which was hung just enough to turn on. As soon as it dropped, the pump shut off. It is very dry in that compartment. Like dusty dry. We must have hit enough rough water to bounce the float up and keep it there since it has no lubrication of any kind. My tapping wasn't enough to get her to drop.

So it seems both pumps are wired so that power through any source (float switch or helm switch) will cause both pumps to run. When I cut the wires to the bilge float switch, it was actually receiving power via the cabin float switch.