Originally Posted by GradeA_TireFryer
yes i would upgrade your grounds - battery to chasis - chasis to engine
this should not ever induce noise into a system - but do the opposite -
try this measure the impedance from your battery - to chasis ground
now measure from amp ground to battery - the lower the number the better...
i have see great systems that can not get engine noise out of
i did this simple test and found a 10 ohm resistance in the ground (the cars factory ground was to a fender - fender bolts were loose..) i tightened bolts added a 1/0 gauge ground from battery to frame and then frame to engine block. all noise gone.
this car had been to 6 shops prior to me before i found it - it was a top isaca finisher that year....
bad quality engine to ground wires can run into noise pros with adding an additional ground wire. If you do as Tirefly says and tighten(or better yet remove) the factory ground you can eliminate that risk. I do think that the Bat to ground and alt to bat should always be upgraded even if you arent running high draw equipment. My car starts faster and the lights dont dim when I roll the windows up etc...