Electrical Getting good ground in 1991 Fox Vert for amps - getting popping noise when I turn on the lights?

[gvanginkel403]

I suspect that you have [ground loop] condition.

That is: A differential between your ground points exist (one ground is better/worse than the others). Having multiple amps connected through multiple grounds with different potentials comes back to haunt you because current is now travelling through the ground connection to each other.

Go through all your engine and body grounds. I refer to the original ground and their associated cables and connections on the car itself. If after that, you're still having noise issues you might work on grounding your equipment at single point or bonding your grounds together through a bus.

This is in addition to the suggestions made above about your cable sizes.

I realize that this is not apples to apples (because it's not automotive) but it still explains the issue:


View: https://www.youtube.com/watch?v=xUFkMqC_nlQ

thank you for this one @Noobz347

This solved the problem. I rand a new ground wire in 16GA from the head unit back to the trunk and grounded to the same bolt the SUB amp is grounded to and it cleaned up the sound. No more light switch pops and hums. Thanks again to the forum for still being active on these great older cars!