I am used to putting my old boat on the trailer and killing the master switch. I just bought a Doral 270SC. Obviously I want the bilge pump to work but not really anything else is necessary (I assume). First, this boat has two master switches. If there is anyone that can tell me which one controls power to the bilge pump, that is greatly appreciated. Second, I need to know if it is 'automatically on' by the float switch or not or what switch setting should be set so it is protected. I don't want to find my boat under water by four ropes. Anything else you can tell an old boater but in water 'newbie' is greatly appreciated.
Never kept a boat in the water before
- Thread starter sbbamafan
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By all rights, the bilge pump(s) are wired direct to the battery.
To check this, turn the battery switch to off and manually manipulate the float to see is the pump turns on.
Ideally, when you leave the boat, the battery switch should off. That would leave only the bilge pump and Mercathode
(Or Volvo equivalent) on.
To check this, turn the battery switch to off and manually manipulate the float to see is the pump turns on.
Ideally, when you leave the boat, the battery switch should off. That would leave only the bilge pump and Mercathode
(Or Volvo equivalent) on.
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Corrosion and sinking are the biggest two risks. And damage from bashing up against docks and piling.
What Steve said - there are a million ways to wire a pump, need to pull the switch up, and see if it activates. The safest way, in theory, is wired to the battery, with a fuse. I personally don’t fuse a bilge pump line, but I believe “code” ( abyc) says you should.
What outdrive does this boat have on it? If it is a bravo three, you need power on to the ‘mercathode unit when the boat is in the water - else you are going to have corrosion problems. Even with the mercathode, you may have corrosion problems. You can test the potential to see if you are protected. Google it, or have a merc mechanic test it for you. Very important ( if you have the bravo 3).
What Steve said - there are a million ways to wire a pump, need to pull the switch up, and see if it activates. The safest way, in theory, is wired to the battery, with a fuse. I personally don’t fuse a bilge pump line, but I believe “code” ( abyc) says you should.
What outdrive does this boat have on it? If it is a bravo three, you need power on to the ‘mercathode unit when the boat is in the water - else you are going to have corrosion problems. Even with the mercathode, you may have corrosion problems. You can test the potential to see if you are protected. Google it, or have a merc mechanic test it for you. Very important ( if you have the bravo 3).
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While galvanic corrosion occurs more rapidly in saltwater, my understanding is that the mercathode is absolutely required in fresh water. Think about it, immersing two dissimalr metals in an “electrolyte”, the same process which creates a battery, is what causes corrosion. Your battery isn’t filled with saltwater, yet it still generates current.
And I believe the potential test should still be done - to determine if you are over, or under protected.
And I believe the potential test should still be done - to determine if you are over, or under protected.
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Don’t forget bottom paint..
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You re going to have to check if the pumps turn on when you lift the float switch with the battery switch off
While the manual helm switches are normally powered thru the battery switch, the float switches should be always on. Sometimes power to the float switch comes straight from the battery with an in-line fuse. Ideally it should be coming from the always on terminal of the battery switch with a circuit breaker. Should the switch fail... no let me rephrase... when the rule switch fails this makes it easy to turn off power. Or if the rule switch stays on and burns the pump you will spot the Off breaker right away
Powering from the switch also eliminate the risk of someone forgetting the wire when replacing batteries.
At to the pump, you need at least 2 and nothing less than 1500 to 2000 GPH. Not the pos 750s most builders use.
On the little 26’ sailboat I build and keep on a mooring I have 3 1500s... my 53 now has four 3700 and I plan on adding two more ...
While the manual helm switches are normally powered thru the battery switch, the float switches should be always on. Sometimes power to the float switch comes straight from the battery with an in-line fuse. Ideally it should be coming from the always on terminal of the battery switch with a circuit breaker. Should the switch fail... no let me rephrase... when the rule switch fails this makes it easy to turn off power. Or if the rule switch stays on and burns the pump you will spot the Off breaker right away
Powering from the switch also eliminate the risk of someone forgetting the wire when replacing batteries.
At to the pump, you need at least 2 and nothing less than 1500 to 2000 GPH. Not the pos 750s most builders use.
On the little 26’ sailboat I build and keep on a mooring I have 3 1500s... my 53 now has four 3700 and I plan on adding two more ...
I drove the 60 miles round trip to the lake to test last night. The bilge pump is wired independantly of the masters and, more importantly, it works! That just leaves me to figure out why there are two masters and what each one controls....
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Safe to assume this boat has one motor, and an electrical panel somewhere with breakers for the “house” dc circuits? And two batteries?
Don’t forget to look into the mercathode, if you have a bravo 3 drive. Boats sometimes sink, but boats with older bravo 3 drives that are unprotected ALWAYS corrode.
Don’t forget to look into the mercathode, if you have a bravo 3 drive. Boats sometimes sink, but boats with older bravo 3 drives that are unprotected ALWAYS corrode.
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Au Contrere (or however you spell it). I have 2 Alpha 1 Gen 2's that if each didn't have Mercathodes, they would be eaten up in a year or 2! The fact that I have SS props makes it even worse. I have to change magnesium anodes every year (which is usually only 5 month max in the water)
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alk is absolutely correct in respect to corrosion. Bravo 3's are really bad about corrosion. If in freshwater you want to do two things. One is make sure you use magnesium anodes. This is an absolute must on a Bravo 3. Second you can double up your protection by having two mercathode units. Buy the second unit with "pucks" for the transom. Contrary to belief, you cannot "over mercathode" a drive. All of this is contained in the Mercruiser Guide to Marine Corrosion". If you cannot find a copy, drop me an email to
gbwest (at) bellsouth,net. I have it in PDF format.
gbwest (at) bellsouth,net. I have it in PDF format.