Rocker switch with light

[Stingo]

I have a rocker switch with an illuminated rocker. There are three prongs labled supply, load & earth. I have used a volt meter to check the continuity between the three prongs.

1: between load & earth there is ALWAYS continuity no matter if the rocker is on or off.
2: there is no continuity between the supply & earth in the off position and there is continuity in the on position
3: there is continuity between supply & load in the on position and none in the off position

Can anyone tell me which prong should have what connected to it. ANYONE that tells me to put the neg onto the earth prong should be ashamed of themselves - that will blow the fuse because there's continuitybetween the earth & load.

Thanks

John

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[bedouin]

I think you'll find the "continuity" between "load" and "earth" is the filament of the illumination bulb.

Connect the battery to supply, the negative to earth and the load to load.

 

[Stingo]

Did exactly that and it melted the earth wire

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[stamfordian]

sounds to me you have a either broken rocker or theres water in the switch,the earth terminal is the negative for the ilimination lamp,it melted becuse it shorted out live to neutral.Loks like a new switch is in order

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[Stingo]

Thanks

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[bedouin]

In that case I would recommend that you fit a fuse of a size appropriate to the wiring. Clearly there is a fault either with the switch itself or in the load attached to it.

Actually on reflection, it is not usual to connect the earth to the switch at all on the type of switches usually installed in boats. It is possible that the earth is purely for the bulb, and not the load

 

[Strathglass]

You perhaps need to borrow a meter that will differentiate between between 'continuity'(well under an ohm) and a 'light bulb' (perhaps between 1 and 50 ohms).

Normally one would expect the indicator bulb to be connected internally between 'load' and 'earth', the supply +ve would be connected to 'supply', the supply -ve to earth and the load between 'load' and 'earth'. Setting the switch to 'on' connects supply to load. If this does not work the switch is faulty.

It would function to an extent if you made no connection to the 'earth' on the switch, connected your supply +ve to 'supply', the 'load' to your load and the other side of your load to your supply -ve, but the indicator would not come on.

Iain

 

[lauradee]

thats what i thought

stu

 

[aod]

he he he...........! If this is for the water maker that I sold to you I also had the same switch and the same problems and it took me an age to work out.

Obviously I do know the answer because I have been through the same experience and I am willing to share the solution after you have bought me a pint (the locals will fall down with shock) this coming weekend at the Castle.

Smug from Essex

 

[Trevethan]

The way it works on my panel is that power comes into the switch from the circuit breaker via the topmost prong (opposite the earth) energising one half of the switch. Then run the live (+ve) wire to your appliance off the middle prong, and from appliance back to battery -ve (or bus bar). This should provide you with on-off function, but no light.

Take another lead from the earth prong and lead that to battery -ve (your bus bar). The light should now work too when the switch is on.

Hope it helps,

Regards,

Nick



She had a deep, throaty, genuine laugh, like the sound a dog makes just before it throws up

 

[halcyon]

Is this a trick question ?

The supply goes to supply
Load goes to what ever your switching on.
Earth goes to earth, bulb is between load and earth, so lights when you switch on.


Brian

 

[oldbasscat]

Hey every one, I'm in need of some assistance. I have an older (70's model) Johnson motor and throttle controls. It was previously rewired to two rocker switches. The first was to activate neutral and the second was to activate forward and reverse. I blew the first switch and decided just to replace both with one three way switch, where center position would be neutral and up forward down reverse. But I'm not sure on how this needs to be done properly. I don't believe I need the ground any more because it was just to illuminate the lights on the previous switch. But I have two wires still to each switch. My load and supply. I figure I need to put both loads together and run it to my new switch as they are the battery, correct? And then simply put my forward to the top of the new switch and my reverse to the bottom. Does this sound correct? Any one can help please. I'm not the most educated when it comes to electronics on boats. Thanks

 

[nigelmercier]

Resurrected thread alert!

RESURRECTED THREAD ALERT!

To oldbasscat, I suggest you start a new thread.

 

[johnphilip]

he he he...........! If this is for the water maker that I sold to you I also had the same switch and the same problems and it took me an age to work out.

Obviously I do know the answer because I have been through the same experience and I am willing to share the solution after you have bought me a pint (the locals will fall down with shock) this coming weekend at the Castle.

Smug from Essex

" PBO forum exists for the free exchange of information and help."

 

[lpdsn]

I wonder if the OP ever figured it out.

 

[William_H]

Regarding the switch and light. obviously if the earth wire melted then there is a short in the switch where the lamp should be. try dismantling the switch as if to remove the lamp to check for foreign objects that might short the lamp. Using a typical digital multimeter is a bit tricky. Firstly the resistance of an incandescant lamp is very low until it heats up so measured DC resistance might be only a fraction of operating resistance. (R=E/I). Secondly the multimeter will be fairly inaccurate at less than 5 ohms or so.
A low ohm meter can be made by setting up a LM317 as a .1 amp (100ma) constant current source from a battery of at least 6v. You then measure the voltage drop with Digital Multimeter ie 200mv range.
So 200mv drop with .1 amp is 2 ohm. and will measure resistance accurately down to less than .1 ohm. Must be useful sometimes olewill

 

[VicS]

Regarding the switch and light. obviously if the earth wire melted then there is a short in the switch where the lamp should be. try dismantling the switch as if to remove the lamp to check for foreign objects that might short the lamp. Using a typical digital multimeter is a bit tricky. Firstly the resistance of an incandescant lamp is very low until it heats up so measured DC resistance might be only a fraction of operating resistance. (R=E/I). Secondly the multimeter will be fairly inaccurate at less than 5 ohms or so.
A low ohm meter can be made by setting up a LM317 as a .1 amp (100ma) constant current source from a battery of at least 6v. You then measure the voltage drop with Digital Multimeter ie 200mv range.
So 200mv drop with .1 amp is 2 ohm. and will measure resistance accurately down to less than .1 ohm. Must be useful sometimes olewill

The original thread is over 10 years old.
Oldbasscat has reposted his recent question as recommended.

See http://www.ybw.com/forums/showthread.php?398036-rocker-switch-help

 

[nigelmercier]

The original thread is over 10 years old.

Now do people see the problem of resurrecting old threads?
http://www.ybw.com/forums/showthread.php?396099-Request-lock-on-resurrecting-old-threads