I put together a system about 5 months ago, alpine unit 9886 with infinity kappa components and kappa 6x9's in the rear deck. I noticed that the lights on the stereo would flicker with the volume up to 18 but it really didn't bother me. Couple months later i added a orion cobalt amp running 400rms to a single sub, not only does the lights flicker the whole unit cuts off when im at a stand still but fine when im in motion. I disconnected the amp and it does it now with just the radio running the kappas. Im thinking this could be the ALT but its been many years out of the car audio game to where im not sure, any suggestions??

 

Sounds like your power/ground wires to/from the deck are too small or you just have a bad ground for the deck. Both of those would create a voltage drop, causing the lights to dim and the unit to go into undervoltage shutdown.

 

sounds good, I'll run the ground outside of the harness like it was suppose to be anyways and see what that does.

 

Works like a charm, thanks man

 

Glad to help.