Mayfair Float Switch and Bilge question

chris16371

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The 800gph has a 3 amp draw but calls for a 4 amp fuse and I have literally almost went to every store with an electrical section within 30 miles and I can't find a 4 amp fuse anywhere. I know a 5 amp would be to much, would a 3amp work? I have plenty of 3's, good thing that's what the aerator calls for.
 

alldodge

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If it calls for 4 I would put a 5 amp in it. The 5 amp will blow if it shorts out
 

chris16371

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My float switch isn't working, can someone explain how it's suppose to work? With the dash switch off does bilge stay completely off then flipping to on will keep it off until water tilts the float switch? Or with the dash switch on the bilge stays on continually and when off it stays off until water tilts float switch? My guess is in off position it stays off since it cuts the current at the switch correct?

The bilge stays on when I have the dash switch on and moving the float switch around won't shut it off, with the dash switch off position I move float switch around and nothing happens.

Is there a way to get the float switch working properly or am I better off just buying a new one? I have no idea how the previous owner secured it to the floor, no visible screws so my guess is epoxy which I'm not excited to try and remove.
 

alldodge

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Your diagram has two feeds to the pump. One goes thru the float switch and the other goes thru the helm switch. Since the helm switch works then that circuit is good.

The other lead comes from the bat to the fuse, to the float to the pump. So with the helm switch off find out if you have 12V at both sides of the fuse. If you have power at the fuse, and the wiring from the float to the pump is connected, then it must be the float switch

Matter of fact I would use a 10 amp fuse instead of a 5
 

chris16371

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Your diagram has two feeds to the pump. One goes thru the float switch and the other goes thru the helm switch. Since the helm switch works then that circuit is good.

The other lead comes from the bat to the fuse, to the float to the pump. So with the helm switch off find out if you have 12V at both sides of the fuse. If you have power at the fuse, and the wiring from the float to the pump is connected, then it must be the float switch

Matter of fact I would use a 10 amp fuse instead of a 5

I have it wired exactly like in the diagram I posted on page 1. Brown pump + brown float twisted together and placed in one side of connector then other side of connector has 1 wire crimped in to connect it with the the 2 brown wires (float, pump) and runs to dash switch and then another wire from dash switch back to fuse (I have 5amp in will change to 10) then to battery. I have the other float wire going to a 3amp fuse then to battery. That's correct right?

I'll have to figure out how to get the float switch out and see if I can get it open and clean it up some. I'll test to see if I have 12v on both sides of fuse.
 

alldodge

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My guess is the 3 amp fuse blew, put a 10 amp on it as well, or at least a 7
 

chris16371

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My guess is the 3 amp fuse blew, put a 10 amp on it as well, or at least a 7

The fuse wasn't blown but I will put a 10 amp in though.

The ball in the float switch doesn't seem to be moving well, might be gunked up. I had to clean and shop vac the whole back storage/bilge area, lots of stuff I wouldn't want running in the pump and getting in the switch. I ended up ordering a Johnson float switch, looks to be the same shape and size as the Mayfair so I'm hoping it fits in the bilge, not much room in there. I'm going to see if I can tear the Mayfair switch apart and get it working, I could of done that instead of buying the Johnson switch but I figured it was only $12 and it's never a bad idea to have spare parts. If the new switch doesn't work then I must of screwed something up lol.
 

chris16371

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Why I wait for the new switch to arrive I have a question on float and bilge placement. The bilge isn't very big so I have limited space to work with and there's very few ways I can place everything. Current setup: Aerator pump is toward the right in the bilge, float switch in front and turned so the switch tilts up toward starboard, bilge pump right behind it. The only other ways I could situate it would be to put float in the back and tilt toward starboard (or port) and place bilge in front. The other way I could would be to put the float switch in the middle (I think I have enough room) with it turned so it tilts toward the bow (or stern) and place bilge next to it. Which way would be the best? Thanks!
 

alldodge

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Which way would be the best?

I cannot say where would be best, just some comments. The switches don't last forever and being able to get at them is best. Most often the switch is forward, the pump is placed lower. The pump cannot get all the water out, and in most cases the switch mounted a bit higher then the pump. Most switches I've had start having trouble turning on as they get older, so don't have anything real close above them.
 

chris16371

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The bilge is slanted up toward the front so I will mount the pump in the back and float toward the front so it's higher. I will have to mount it sideways like the old one, mounting it any other way will put the switch at an angle bc of the slant and I'm sure I want it on a flat surface so probably best to mount it like the old one was.

I didn't know Johnson made the Mayfair switch, the one I'm getting must be the same thing with a different logo. The Mayfair says 15 amp switch on the logo, I'm assuming the new one will be the same. Do I need to use a fuse higher than 15 amp or is 10 amp still ok? Does the wire that goes straight from battery to float need the same size fuse as the one that goes from battery to dash switch back to the float and pump wires connected together or do I use a different size fuse for each connection?

The float should be here today so that should be the last of my questions, unless it doesn't work. Thanks for putting up with my questions and the repeated ones. I really appreciate the help!
 

alldodge

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The amp rating on the switch is how many amps it can take, and it should always be able to handle more then what its controlling.

I would use 10 amp fuse on both sides basically because it will blow before the wire or the pump will melt. So it protects everything and if the pump stalled and didn't start spinning right away, there is room for the pump to draw a bit more to start up
 

chris16371

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May 19, 2017
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The amp rating on the switch is how many amps it can take, and it should always be able to handle more then what its controlling.

I would use 10 amp fuse on both sides basically because it will blow before the wire or the pump will melt. So it protects everything and if the pump stalled and didn't start spinning right away, there is room for the pump to draw a bit more to start up

After installing the new float switch everything is working correctly.

Just want to say I'm truly thankful for you checking in on this thread and helping me figure all this out. Would of took way longer to do so on my own. I appreciate all your help and again thank you!
 
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