I Need Ur Help

I Bought A Line Level Converter I Guess For The Factory Stereo And I Hooked Up The 8 Colored Wires To It And I Have The Amp Nd Subs And Everything Hooked Correctly But The Stereo Doesnt Turn On When Everything Connected So I Take Out Everything And I Connect The Wires Together W.o The Converter And It Works But The Fuse Blows Am I Supposed To Connect The Grey Red And White Wires Instead Of The Colored Ones Or What?? Ive Been Working On This All Week I Need Help

what line level convertor ? can you scan and post the intructions with the schematic ?