Wiring Up an Eckon Off Indicator to a 3 Aspect Signal

[BR(S)]

I have recently put together an Eckon ES101 Off Indicator and want to wire it up to a three aspect Eckon signal, which is proving more difficult than I thought it would.  I'd like to wire the Off Indicator so it lights up when either the yellow or green aspect are being displayed.

 

The three aspect signal and switch are wired in what I assume is the "usual way".  I am using a 6 pin ON-ON-ON toggle switch with three pins feeding the signal aspects, one connecting to the 12V DC power supply and the remaining two being bridged with a piece of wire.  The signal has one wire per aspect colour connecting to the toggle switch and a fourth wire with resistor that connects to the 12V DC power supply.   

 

The Off Indicator LED has two wires coming from it: one with resistor for the negative feed and the other for the positive feed.  The difficulty I am having wiring the Off Indicator is that in trying to get it to work with either the yellow or green aspect, I can only see how to wire it in a way that the positive wire from the Off Indicator to the green aspect energises the wire for the yellow aspect and vice-versa, so that when the Off Indicator lights, both the yellow and green aspects light up at the same time. 

 

Any help on how to wire the Off Indicator so that it lights with only the green or yellow aspect and doesn't light the two aspects up at the same time would be appreciated. 

[Dagworth]

put a diode from the green terminal of the switch, and another from the yellow. (Both diodes the same way round)

Connect the other ends of the diodes together and connect the connection to the Off indicator.

 

The three black circles are the connections from the switch, hope that makes sense

 

Andi

[BR(S)]

That's great, thanks.   Diodes are not something I've used before, so I'm glad it wasn't me missing something that should have been obvious to me!