Parasites noise problems

Hello!! The other day I bought an audio interface to plug it into my car radius. I installed it and goes wonderfully with the car stopped, but when starting it and going, small cajiditos on the speaker are sometimes heard. I called the company to buy it and told me some parasites produced by the dough. The cable has two disconnected dough cables that apparently have to join and he told me that if united towards noise tried to release them. The fact is that united and loose the small noise follow. Does anyone give me a solution?

Hi Nacho1982, there are some filters that are sold (they are those square boxes) and are installed at the entrance of the self -art, they serve to filter these parasitic noises that usually come from the ignition of the engine. There is also the option to attach a condenser in the 2.2 microfrades ignition coil.

Where do they put exactly ?? Could you put any photo?

Hi Nacho1982, the filter, goes in the positive from the device to where you connect it, but if it is attached to the + radio, put it later, so that the two devices seem together (I do not know if I explain myself). If you choose to put a capacitor too, this carries a cable that would have to connect to the + that feeds the coil and the body is screwed into a dough. Also say that in the alternator it usually carries a condenser that is connected to the positive and screwed to dough (it may be that it is broken). Greetings!!