Pyramid PB779X Car Audio Amplifier "dim lights wont work brights" Questions

...dim and not as bright as it usually is. when fully on. i then took my amp home and hooked it up a computer PSU and it works just fine, the red light is bright and fully powered... why wont it work in ...

...work similarly, maybe I'm wrong. Any suggestions? Anyone have a decent schematic? The IRFZ46N are n channel high speed switches . They basicly drive the Mosfets. Sounds like you have some problem ...