Sealine S23 Wiring Expert needed...

[pau1gray]

On our S23 I noticed that the bilge pump works but only through the main switch and not the float switch. My initial thought's were that the float switch was U/S.
There are three wires that lead to the bilge pump and Float switch - Black which is the -ve and goes directly to the pump, Brown which is the positive feed from the bilge pump switch and a grey lead - which is attached to the float switch then connects into the brown lead. So when the float switch rises it provides 12V to the pump.

With everything disconnected the float switched showed open circuit when down and closed circuit when up - therefore the float switch is working.

When measuring the voltage between the grey and the black there was 12V shown on the meter, but when I put a bulb across the grey and black it would not light??

On looking at the wiring diagram it says that the float switch is powered from a fused supply in the service box (which all seemed to be correct - break fuse no volts - reset fuse then 12volts on the grey lead to the black lead) - but the lead is Blue/red at the fuse box and not grey.

I tried to chase back the grey cable but it disappears into some foam and I can't find where is comes out. I've also tried chasing the blue/red cable but that disappears into trunking somewhere in the service box.

Does anyone know whwhere these two cables go???

I have made a temporary fix by running an aditional wire to provide 12V to the float switch but this does not fix the problem rather just hide the symptom.

Any thoughts greatly appreciated??

 

[lenseman]

[ QUOTE ]
With everything disconnected the float switched showed open circuit when down and closed circuit when up - therefore the float switch is working.

When measuring the voltage between the grey and the black there was 12V shown on the meter, but when I put a bulb across the grey and black it would not light??

[/ QUOTE ]
I think the answer lays in the above two paragraphs. The first states that the bilge switch closes when it raises, ie when the boat fills with water.

The second paragraph says that there is 12 volts when measured with a meter and 'nothing' to light a lamp?

The internal resistance of the meter will be at least 20,000 ohms per volt possibly 50,000 ohms per volt and as such shows a huge resistance to the voltage being measured (240k ohms or possibly 600k ohms). When you put a lamp across these two wires, the very low resistance of the lamp will virtually short out this supply and as a consequence the lamp will not light.

The ultimate test to 'prove' the bilge switch would be to short out the two terminals with a piece of wire, effectively closing the contacts. If the pump works during this test, the bilge switch has a high resistance (HR) contact and needs cleaning or replacing. If the pump still fails to work during this test then the HR is to be found else where and you will need to chase/prove the wiring back to the main supply until you find a slightly loose screw contact which will be causing the HR.

I hope this helps?

 

[halcyon]

The bilge pumps used to be dual supplied.

The fuse supply was perminant live and supplied the float switch.

There was then a switch on the helm, or cabin depending on pump location, that supplied the pump direct via a circuit breaker on the main panel.

The 12 v you see is possibly a leakage feed breaking down with the bulb load.

Check out bilge pump switch, and if there is a circuit breaker.

Brian

 

[volvopaul]

Simple its the switch, testing with a meter is not always the answer, the switches do show a contact across with the meter but will not take any load, I always take a switch with me when asked to do a repair 9 times out of 10 its the switch, unless its a supply problem or bad corroded wiring.