AFR gauge HELP ME PLEASE!!!
 

Don't understand what i'm doing wrong, my car is a 93wrx, i've fitted an autogauge afr, 3 wire out the back of it red,live, black,earth, grey, singal, correct?
My live and earth are coming from the same place as the boost gauge also autogauge. The grey signal wire comes from down my the ecu plug b43, pin 6, white wire with siver tabs round it, is this the right wire??? I've just done a multimeter test and i'm only getting 0.4 from it! Is this because i've used scotch locks???? or is it just the wrong wire, voltage hardly moves when i rev the car either. The gauge does hardly anythin just has a fit at times and thats about it. Have i done all this wrong or is the gauge just broken???
Please help as it's really annoying me now!
Thanks.

Now removed the scotch lock and soldered it together. Still no joy though it just has a fit then nothing, although when you turn the lights on it flickers as the lights go on then nothing again????? Is the gauge just shagged???