IF circuits are wired as follows
http://ts1.mm.bing.net/th?q=EZ+Turn+...re+LED+D ash+

the LED does not light.

But if wired like this

http://www.xtremelandy.co.uk/Manuals...m%20(JPEG).jpg

the circuit works with power to unit and lit LED

I do not know why a second unit cannot go between LED and grnd with a dummy load unit to grnd in power to unit as the center take off prong €¦thus skipping the relay. For an alternative example €¦. As the posted question asks

near 9/10 circuits I wired are direct connection to Batt with wire gauges supplied by Powerstreams calculator. But there are places without space or necessity that could be wired without a relay n without loss of voltage.

http://www.powerstream.com/Wire_Size.htm

there are extra LED on the shelf but that's more complication.