Whenever I have the radio on in the car and I switch on the HVAC blower, I can hear a constant crackling sound through the speakers. I can also hear a momentary crackling sound when I switch my rear wiper on/off.

I'm pretty sure this just started when I switched the Pioneer decks between my car and my wife's car. Her car had an older deck (which actually used to be in my car previously) and I had the newer one, and I swapped them back so I have the older one again, and her car has the newer one (has iPod control and she has an iPod, but I do not).

As far as I know I did not change out or mess with any wiring, other than swapping in a different Aux input cable to connect to my MP3 player's lineout jack. When I have the stereo on the Aux input and MP3's playing, I do not hear any extraneous noises in the speakers, no matter what other accessories are running. The noise is ONLY when the radio is on.

What could be the cause of this?

 

whats up bud
it could be a couple of things like a bad of weak ground wire or if your radio has a i-pod plug or rca plugs that hang off the rear of the unit the metal from these connection could be touching the radio cage or something metal in the dash ...

SO i would try to find a better ground and take a look at your plugs and make sure nothings touching .

Hope this help good luck

 

oops forgot about this thread heh.

Yea I do have an adapter on the back of the unit w/ RCA's attached, which plugs into my mp3 player's line-out jack. I had to switch out the wire running under my console when I put this head unit back in my car, so something could definitely be touching metal back there.