Help with SPST iluminated switch

Hey guys, I have fitted up a spotlight to the back of the Nav so I can see whats going on in the tub at night, it came with a basic 2 prong switch that I fitted inline of the +power cable. I have just purchased a SPST iluminated switch that has 3 prongs on it, I want it to iluminate when the switch is turned on and go out when the switch is off, at the moment I have a +wire from the battery and the +wire from the spotlight, I am guessing I will need another earth or something but I am not 100% sure. If someone could give me the heads up on what to connect to where I would appreciate it.

Thanks

The switches could be configured in several ways, I know I've got some weird ones in my caravan.

You're right, in that you need a ground (negative) to the switch. The way to hook it up is to figure out which one is the earth to the switch, then by touching the positive (from the battery) to the other lugs, determine which one lights up the switch - call this LUG B ... and use the OTHER lug for this wire, then put the spotlight onto LUG B.

This way, when your switch is off, no light will show, and when you turn the switch on, the switch will light up.

I just had a bit of a play with the switch, and for the life of me can not get it to do what I want. I can get the light in the switch to work all the time, or not at all and I can get the spotlight to work when the light in the switch is on all the time or off, but can not get the light in the switch and the spotlight to both be on or off at the same time together. All I want is to flick the switch and have the spotlight and the switch light both come on and when I turn the switch off for both to go out. I think I may have to get an auto elec to have a look at it for me.

one leg of the switch is an earth which is needed to allow current to flow through the indicator to allow it to light up. Sounds like you have your battery +12v on the incorrect pin.Try swapping the +12v from the battery and the +12v to your light. this will let 12v supply the light and the indicator when switched on.

Let me know how you get on

I've drawn a typical SPST illuminated switch with how it should be connected.

If you can get the light to glow no matter which way the switch is, the two legs of the switch are the lower two in the drawing: because no matter which way you have the switch, positive and negative are supplying power to the little light inside the switch.

Try putting the negative lead on the outer leg and positive on the other opposite side, with the wire to the spotlight relay in between.

Thanks guys, I will have another play with it tomorrow morning and see how I go. I will keep you updated.

Thanks heaps, I finaly got it to work now, just have to put a plug on the wire and fit it off now.

Thanks again.