My Bilge Pump/Electrical Issue

[Bad Obsession]

My electrical system is a house bank consisting of two group 27 batteries and I have an aux. battery that is a starting battery. I have a Link 10 battery monitor that monitors my house bank.

My bilge pump is wired so that it goes back to the breaker panel. It has a switch on the panel that can be turned on to turn the pump on or the float switch will engage the bilge pump when the batteries are on. If the batteries are turned off the bilge pump switch and the float switch won't turn the bilge pump on.

When I leave my boat I leave the battery selector switch on 2 so that my bilge pump will run.

Last spring in stalled a new packing gland. Up until then my old packing gland was dripping enough where the bilge pump would kick on every few days. With the new packing gland it barely drips, if any. The bilge pump really doesn't kick on.

After leaving the boat for a month or so I notice that my Link 10 screen is blank. If I lift the float switch up on the bilge pump the pump doesn't kick on. If I turn the hot switch on for the bilge pump it doesn't kick on. If I try to use any of the 12V systems on house bank nothing comes on. If I switch the battery selector to All then the system works fine. If I plug the charger into the batteries and then turn the charger off the battery monitor comes on and says that my batteries are at 100% and all the electronics work.

My batteries seem to be holding a charge. They are 3 to 4 years old.

At this point I am wondering what is going on. I think that I am going to wire my pump directly to the battery so that the bilge pump float switch will kick the pump on even if the batteries are off (this is the way it should be ran anyways).

Anyone have any ideas or suggestions for me? Anyone have a good wiring diagram for doing this?

 

[Bad Obsession]

I have to leave my boat for sometime (a month or so of not using it) for the Link 10 to blank off. When my pump was running more often the Link 10 never blanked out.

 

[Stu Jackson]

Wiring the bilge pump as you suggest is indeed the right way to do it. There was a post about this a few weeks ago, and the way to do it is on the Rule website, and comes with all of their pumps and switches. I added a Rule panel switch with auto/off/manual. Our pump is wired directly to the house bank.

Don't know about your Link 10 issue, though. Have you reset it recently?

 

[Bad Obsession]

I haven't reset the Link 10 in a while. Is that something that I should think about doing?

 

[JVB]

Sounds like a loose or corroded connection (positive or ground) between the house bank and the breaker panel. When you switch to All then the Aux battery runs the systems connected to the breaker panel.. Try cleaning the connections on the house batteries first. If that doesn't fix it, next try to isolate the problem like so: Disconnect ALL of the positive battery cables from all the batteries. (Label them so they can go back in the same places.) Then substitute two jumpers between one isolated battery's bare terminals and the breaker panel. Use a jumper for positive and another for negative. That ought to relight the systems. If it does then one of the cables you have disconnected or its associated battery monitor shunt or the battery selector switch is the problem. Jump around just one part of the links between battery and panel at a time to find where the break is. I am not a marine electrician but I did sleep at Best Western last night.

 

[JVB]

P.S. The battery monitor is basically simple. It's a voltmeter with a fair number of switches. For voltage it is switched to measure across a battery's terminals. For amps it is switched to measure voltage across a resistor, called a shunt, that is between a battery terminal and the thing being powered, i.e. the breaker board. (It can be in either the positive cable path or the negative cable path.) And it could be inside the meter enclosure or external. A shunt is a hefty but low ohm resistor that produces a small (maybe 50 millivolt) voltage drop across it when maybe 50 amps are flowing thru it. The amp reading is really just a voltage measurement which is interpreted to display amps.

http://www.motorcycleproject.com/motorcycle/text/shunt.html

 

[Ed Schenck]

I thought it was Holiday Inn Express. Maybe Best Western is for electrical, can't remember. But Bad O never said where the battery switch was set before he went to "All". If what you are assuming JVB then he should get the same result on switch position #1. At any rate if the batteries are at 12.7 volts then it should not be that hard to find the problem. Since the Link 10 seems to be involved then I vote for looseness or corrosion at the shunt.

 

[Roger Long]

Wiring the bilge pump as you suggest is indeed the right way to do it.?

I don't think so. Why would you ever want to have a situation where the bilge pump could accidentally be turned off? For the rare occasion when you might want to turn it off, pull the fuse. The extra effort of doing so will make you think about it.

The bilge pump should be wired directly to the battery ahead of the battery switch so the whole boat can be turned off and the pump will still protect the boat. If you want to be able to run it without the float switch, wire a switch in parallel to the float switch.

A sunken boat is a big and expensive deal. Remember. Rule likes to sell you those cute little panels. More profit. That doesn't mean they are a good idea.

 

[Bad Obsession]

I think that I am going to reset the Link 10, check the batteries to make sure that they don't have a dead cell, check the shunt and the ground connections, and rewire the bilge pump directly to the batteries. That should take care of the issues (hopefully).