Hi there I have a low voltage reading to my coils on my 1995 wrx I checked the other day and there was 12v and now I've only got 7v and no spark, my coils are all fine I've tried to trace the live wire back to see where the power comes from but can't see where they go, I looked at manual and it said the coils from ecu are spose to be 0 volts so I'm gessing that the earth from the coils run back to the ecu but were does my power come from, the live feed to coils are a yellow wire I checked my ignition box and no yellow wire, ? Many thanks