led trouble (1 Viewer)

[workingdog]

Not the kind of trouble you think.

My son and I hooked up a very cheap pair of lights on our new side by side. I got a set of switches that have status LEDs. When I wire it straight through the switch it works. When I wire it through the LED, the LED works, but the relay for the lights won't trigger and the lights don't go on.

What's going on?

Peter

 

[george_tlc]

You can't wire it 'through' the LED - that pin is just to light up the LED - you'll get minimal current flow (whatever the LED + the internal resistor) allows to flow - not enough to fire the relay, but enough to conduct a little through the relay for the LED to light.

EXACTLY what kind of switch is it? Does it have 3 lugs (2 for the switch + 1 for the LED). You need to know if the LED lug is ground or +12V to light the LED (the other 'end' of the LED will go to a resistor to limit current for the LED and then to one of the switch lugs.

Pictures would help us... and a bit more info regarding the switch

cheers,
george.

 

[workingdog]

It's a two lug toggle switch and two lead LED. So, instead of wiring it through. I take the LED separately to power and let the switch supply it's ground when it grounds the lights - right?

 

[george_tlc]

Yes, use the 2 lugs as the switch for your relay ground side switch. Switching the ground side of the relay, means you wire the +12V to your LED+ and the switched ground to your LED-. Then the LED lights only when the switch provides ground the LED and the relay. Other side of the relay +12V goes to a fuse protected +12V source.

cheers,
george.

 

[workingdog]

Thanks.