New Bilge Pump Install

rss459 · **Posted:** Tue Jun 05, 2012 3:20 pm

I need to replace my factory bilge pump and switch because the connection broke off to the hose. I have not pulled any wires yet or bought a new pump but I am curious how the switch works. Obviously the pump is hot all the time so the float can activate with water present but then there is the manual override when you press the switch on the console. Does this functionality take a pump designed to do this or are the connections made in the switch? I am looking at some of the internal float models instead of the switch/pump combo.

Thanks!!

Randy

ric · **Posted:** Tue Jun 05, 2012 3:41 pm

rss459 wrote:

I need to replace my factory bilge pump and switch because the connection broke off to the hose. I have not pulled any wires yet or bought a new pump but I am curious how the switch works. Obviously the pump is hot all the time so the float can activate with water present but then there is the manual override when you press the switch on the console. Does this functionality take a pump designed to do this or are the connections made in the switch? I am looking at some of the internal float models instead of the switch/pump combo.

Thanks!!

Randy

I've used this one for a year and it's good. http://www.attwoodmarine.com/store/product/Sahara-S500-500-GPH--12-Volt. In hindsight I should have gone with the 750, 500 is slow. On a boat your size? I'd go with the 1100gph model.

Wiring? Simple. The wiring coming out of the bilge pump one goes to ground, one goes to battery + and one goes to a switch that is switched + to turn on at will. Carling switches will light up the LED when it comes on automatically to tell you its... on.

fiznuka · **Posted:** Tue Jun 05, 2012 7:00 pm

Wiring diagram should come with the pump that you purchase as for the boat wiring you will just need a test light to find your batt, switch hot, and ground wires. I would also go with a bigger pump.

rss459 · **Posted:** Tue Jun 05, 2012 8:25 pm

I read the Attwood install instructions and I see how it works now. I will most likely go with a 1100 gph model.

Thanks for the helpful advice!!

Randy

Paul I. · **Posted:** Tue Jun 05, 2012 8:39 pm

rss459 wrote:

I need to replace my factory bilge pump and switch because the connection broke off to the hose. I have not pulled any wires yet or bought a new pump but I am curious how the switch works. Obviously the pump is hot all the time so the float can activate with water present but then there is the manual override when you press the switch on the console. Does this functionality take a pump designed to do this or are the connections made in the switch? I am looking at some of the internal float models instead of the switch/pump combo.

Thanks!!
Randy

Most auto pump are made to do what you want. BUT, you still want that helm switch! You might/need to empty out bilge at will. I can aways get out 1 or 2 gals of water by turning it on myself. It generally takes more water to get the float higher to turn the pump on.

Myself, I alway add a 2nd pump to my boat. CHEAP ins. if one fails!!

Most auto pumps have 3 wires, ground (-) black,constant +12V) brown, switched (+12v brown & white)

weather · **Posted:** Wed Jun 06, 2012 8:12 am

This is a good article I found on the subject: http://www.yachtsurvey.com/bilge_pumps.htm

If you are going to install a larger volume pump than original, keep an eye on your hose size - this will determine the maximum size pump you can install, before you need to add another through hull and hose of a larger ID. Most pumps I have seen are 3 wire - ground, battery hot and switched hot. Also keep in mind your existing wire gauge and fuse/breaker size. No point having an automatic pump if it trips the breaker or melts the wires when it turns on.

This is the pump I used when I replaced my forward bilge pump: http://www.boatersland.com/rm1100.html You secure the base, and the top comes off with a couple of clips (I think a lot of them do this), also the float is internal so only one part to mount, and objects in the bilge are less likely to interfere with the float since it's internal.

Paul I. · **Posted:** Wed Jun 06, 2012 9:13 am

Very good article!!

This is more important on smaller boats because the they can get overwhelmed quicker than a bigger boat.

What the article went into too, that most boaters don't understand. Is the GPH rating. A 500GPH pump, will do that only at its own level. Now put a hose on it (a smooth inner hose works better) and raise it 2ft with 5ft of hose. Now your down to 350gph, give or take!

rss459 · **Posted:** Wed Jun 06, 2012 4:26 pm

I just pulled the old pump out and it was only a 650. I want to put in an 1100+ but I only have a 3/4 inch line and getting to the the thruhull is pretty much impossible. Looks like I am stuck at 750 gph.

Also my boat has 4 wires. 1 is black so ground bit the others are all brown so O will get the meter out.

Thanks

ric · **Posted:** Wed Jun 06, 2012 8:05 pm

I thought about putting a 1100gph on 3/4... I need to research more, I don't think damage will occur it will just kinda be a little more pressure. You know... water shooting 10ft out the side of the boat. It would be quite funny honestly.

rss459 · **Posted:** Wed Jun 06, 2012 8:50 pm

Water shooting 10ft would be funny but wwould the pump overheat or have reduced life? On the trailer the bilge pump drenched the wife once when I was hosing out the boat. She was not so happy. :evil:

But back to business.

I pulled out the trusty meter and found out that the square black wire is ground of course, one of the browns is hot, and the other 2 are switched. The switched ones are jumpered together at the connector. Must be a custom wire for the attwood 625 and separate switch that came from the factory. Either way should work just fine. If the wires are brown/white I cannot tell. Too dirty.

Randy

weather · **Posted:** Thu Jun 07, 2012 7:30 am

rss459 wrote:

Water shooting 10ft would be funny but wwould the pump overheat or have reduced life? On the trailer the bilge pump drenched the wife once when I was hosing out the boat. She was not so happy. :evil:

But back to business.

I pulled out the trusty meter and found out that the square black wire is ground of course, one of the browns is hot, and the other 2 are switched. The switched ones are jumpered together at the connector. Must be a custom wire for the attwood 625 and separate switch that came from the factory. Either way should work just fine. If the wires are brown/white I cannot tell. Too dirty.

Randy

Are there 4 wires going to the pump, or just coming to the connector from the boat, then 3 to the pump, with two switched wires (boat side) jumped together to the one switched on wire to the pump?

Paul I. · **Posted:** Thu Jun 07, 2012 8:02 am

rss459 wrote:

I just pulled the old pump out and it was only a 650. I want to put in an 1100+ but I only have a 3/4 inch line and getting to the the thruhull is pretty much impossible. Looks like I am stuck at 750 gph.

Also my boat has 4 wires. 1 is black so ground bit the others are all brown so O will get the meter out.

Thanks

Put a 2nd pump in?? Cheap insurance and you will have over 1100GPH! Wire it to your 2nd battery if you have one.

rss459 · **Posted:** Thu Jun 07, 2012 9:31 am

weather wrote:

rss459 wrote:

Water shooting 10ft would be funny but wwould the pump overheat or have reduced life? On the trailer the bilge pump drenched the wife once when I was hosing out the boat. She was not so happy. :evil:

But back to business.

I pulled out the trusty meter and found out that the square black wire is ground of course, one of the browns is hot, and the other 2 are switched. The switched ones are jumpered together at the connector. Must be a custom wire for the attwood 625 and separate switch that came from the factory. Either way should work just fine. If the wires are brown/white I cannot tell. Too dirty.

Randy

Are there 4 wires going to the pump, or just coming to the connector from the boat, then 3 to the pump, with two switched wires (boat side) jumped together to the one switched on wire to the pump?

4 to the pump. It appears that the 2 switched wires go 1 to the pump and 1 to the float. Here at work I do not remember how the boat side off the switch was wired except for the jumpers across the back of the switch. I will look tonight. I think for pumps that include the float with a typical 3 wire setup I can make it work easy enough by just capping off the 4th wire. The jumper is crimped into the connector so I'm not going there.

rss459 · **Posted:** Thu Jun 07, 2012 8:55 pm

Paul I. wrote:

rss459 wrote:

I just pulled the old pump out and it was only a 650. I want to put in an 1100+ but I only have a 3/4 inch line and getting to the the thruhull is pretty much impossible. Looks like I am stuck at 750 gph.

Also my boat has 4 wires. 1 is black so ground bit the others are all brown so O will get the meter out.

Thanks

Put a 2nd pump in?? Cheap insurance and you will have over 1100GPH! Wire it to your 2nd battery if you have one.

Can I run it out the same hose with a T fitting? What about back pressure on the other pump? I wonder if a one way valve would work?

Paul I. · **Posted:** Thu Jun 07, 2012 9:54 pm

rss459 wrote:

Paul I. wrote:

rss459 wrote:

I just pulled the old pump out and it was only a 650. I want to put in an 1100+ but I only have a 3/4 inch line and getting to the the thruhull is pretty much impossible. Looks like I am stuck at 750 gph.

Also my boat has 4 wires. 1 is black so ground bit the others are all brown so O will get the meter out.

Thanks

Put a 2nd pump in?? Cheap insurance and you will have over 1100GPH! Wire it to your 2nd battery if you have one.

Can I run it out the same hose with a T fitting? What about back pressure on the other pump? I wonder if a one way valve would work?

No, install a new thur-hull and hose. It should not take you over 1hr to do.

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New Bilge Pump Install

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