Bilge pump wiring

[Painkiller]

View attachment 124645

I replaced my three bilge pumps and floats this weekend. The first two work fine but the aft bilge pump will not work. I wired black pump to black ground wire, the larger brown wire with the red stripe to grey (float switch), and two brown wires to grey (other float switch wire) and to brown from pump. I validated that the pump is working by touching the battery with the wires. I also put a meter on the wires and found only the smallest brown wire was hot. I did try to hook the hot wire to the pump but it did not start the pump. Any ideas?

 

[Golfman25]

check for a fuse or switch somewhere? I know my emergency pump I wired with an inline fuse.

 

[Lazy Daze]

One of the brown wires runs to your systems monitor. That won't carry 12V by itself - it's a feed wire TO the monitor when the pump is demanded on.

It's a little hard to follow what you're saying, but...

-- Turn the switch on at the dash. Does the pump run? Do you get 12V+ at that crimp connector?
-- Manually lift the float switch. Does the pump run? Do you get 12V+ at that crimp connector?

However, if you put 12V+ directly to the pump's brown wire and got nothing, you should verify your ground is good.

EDIT: added some more info

 

[Painkiller]

No, after hooking up the wires and trying the switch at the dash and the float switch neither turned the pump on...

 

[Lazy Daze]

No, after hooking up the wires and trying the switch at the dash and the float switch neither turned the pump on...

OK, see my edit "however" and the extra info I added to the "--'s"

 

[Painkiller]

OK, see my edit "however" and the extra info I added to the "--'s"

Thanks, I did wonder about that. I cut the ground wire at the butt connector that I put on and touched the pump ground to a grounded screw while the hot wire was on the pump brown wire and got nothing. I figured I would get something if I was touching a grounded screw/wire. Maybe I will try to connect the ground again to verify.

Does it make sense to you that when I disconnected the wires and put a meter on them that I only got power on one of the brown wires? And do you have any idea on why the one brown wire has a red stripe on it?

 

[Bt Doctur]

Typically 1 wire from the float switch runs direct to the battery, the other wire goes to the Brown wire of the pump, also you connect the manual "on" switch wire here also.
The Brown/red stripe should be a constant 12 supply that would go to the pumps Brown wire. Check at the battery for this wire and maybe a inline fuse.
I also run a new ground wire from the pump to the neg battery . If your system wire ground goes bad (Brown/red stripe)you lose the pump

 

[Hoplite808]

@Painkiller, a couple of things;

1) You should reference the wiring schematic for your vessel that is included in the operators manual. It will tell you exactly what wire goes where and does what. On my 1996 270 there are three brown wires, one with a stripe and two black wires in the boats wiring harness. There were two bilge pumps installed. The wiring allows for always hot for automatic function, switched, and a sensor wire for the high water alarm.

2) Your electrical repair may need a repair. You are using 10-12 gauge butt connectors on 14 gauge wires. They are also heat shrink and you never heat shrank them to help make a water resistant seal to help keep corrosion off the electrical contacts. Also why do you have four wires connected together at the one butt connection? Each wire should only be connecting to another single wire I would think unless there are aftermarket modifications. If so it would be better to use a buss connector if you need multiple wires connected together to form one circuit.

 

[ttmott]

 

[Painkiller]

View attachment 124651

I am going to try to get to the boat this afternoon. When I checked the voltage yesterday on the hot wire it was way low. An electronics guy I talk to thought the best place to start would be the circuit breaker. Would the inline breaker be at the main DC breaker panel in the bilge? And do those just switch on/off or is there a way to access them to determine if they are off? Also, is there a fuse behind the DC Distribution Panel in the salon area? Thanks for the assistance.

 

[ttmott]

The wire harness connectors can also be a source of the problem. To understand the connectors you need to reference the electrical schematics in your owner's manual.

 

[Bill Curtis]

All the bilge pumps I have seen are fused off the battery, before the battery disconnect switch (es). That way, when batteries are off, you are still protected from flooding by the pumps. Fuses / breakers usually back by batteries / disconnects.

 

[Painkiller]

Ok, now is the time to put my tail between my legs and tell you that I found the circuit breaker tripped. I did not have time to put the wiring all back together tonight but will try to get to tomorrow. Thanks for everyone's input!