Car is 2004 3.9 Mustang w/ Mach 460 system.
I had an aftermarket radio put in in 2007. All other stuff is stock/Mach 460.
My knowledge of car electronics is limited to none so bear with me.

Recently, I started to hear an buzz coming from my rear speakers that changes pitch with the engine revs. I went behind the radio to see if I could figure it out. I could wiggle one of the RCA cables and the buzz would stop, but it would eventually come back. No idea.

I've read there could be a loose ground? I've checked my voltage with a meter and voltage is fine. 12v off, 14.4v idle.

I had an audio guy tell me it's the amplifier, but I don't want to spend money replacing it without being sure.

Just trying to figure out what's up and what needs to be replaced.

Thanks!

 

Go and get your battery checked.

 

I just replaced my battery because it was spilling acid.

 

Re-ground everything, and ground it to the same point on the vehicle's chassis.

 

Where can I find all of the grounds?