I constantly hear a ticking noise coming from all speakers when radio is on(VW jetta). What could cause this?

Feed back from the alternator armature. You may need a noise suppressor to make it go away. Poor grounds can also give feed back, check them all for security and corrosion.

Quite honestly I have never heard of spark plug wires causing this problem. Not from the speakers anyways. I had the same problem in my Sebring, and it was because there was a poor ground connection. Especially if it is an aftermarket stereo, this problem is pretty common. Check that!

If the fee of the ticking will strengthen with the fee of the engine then you're finding out on up some interference. 2 maximum probable reasons are in the capability line wherein case you'll be able to desire to place in a choke coil (noise filter out) in the capability line to the radio. probability no 2 is interference from the ignition gadget. maximum cutting-side autos are fantastically stable with this, so if it is the source of your noise, you will have something incorrect which incorporate your ignition gadget, like undesirable spark plug wires, coil or perhaps the incorrect spark plugs. This relatively is fantastically uncommon at present so i think you'll be able to desire to place in a noise filter out on your capability line to the radio.

Sit and turn off the motor and listen to the radio. If the clicking goes away, then comes right back when you start the motor, it's probably the spark plug wires.

If this is has a gasoline engine, it is the plug wires.