Use this diagram to diagnose and cure the most common noise problems associated with outboard amplifiers. The general idea is to isolate the specific cause of the noise in your system. If these tips don't solve the problem, it's helpful to be able to call on a Crutchfield technical support specialist. Most products purchased at Crutchfield qualify for our expert tech support. If you purchased your gear from Crutchfield, or purchased tech support separately, you can contact them toll-free between 8 a.m. and midnight Eastern Time, seven days a week. Before you get started, check the fluid in your car battery. Sometimes, noise can be eliminated just by topping off the fluid with distilled water.