Hi all so tonight I installed a new head unit in my car. the previous installer hadn't connected all the speakers so I did that while I was there.

so I put it back together and tested it I worked with no worries.

I then went for a drive and noticed that it was making a popping or clicking noise that was relative to engine speed eg more revs more frequent clicks and a little louder as well..

I used all the same wiring from the previous job so im not sure wether its earth or something else?

any help or suggestions would be appreciated

Are you running an amp? Only reason I ask is it sounds like when you run the amp signal wire with the power cable.

Nah no amp. I should of mentioned that. But it's all good now did some testing and for some reason it's coming through the antenna. I searched around and you can buy antenna noise filters of eBay for under 20 bucks so ill give that a go

or there is an earth fault somewhere between you're antenna and input connector behind your head unit, if the cable has a split somewhere along the way and is rubbing against any exposed metal in your car, this will cause your popping/alternator whine noise... and a filter wont do anything if its the case

Earths can cause many things, this being one of those, I would find a new ground location, sand back any paint, clean it up with degreaser and then bolt your ground tightly to that, otherwise as a test run the headunit ground wire directly back to the negative post of the battery and see what happens.