Odd radio buzzing

[azzfox]

Ive got a problem that has really puzzled me. I put a Pioneer DEH-P4950MP head unit in my car and when I turn the ignition on the speakers buzz. So at this point I thought ok the antenna earth is dodgy. Pulled the plastic wheel arch off to inspect it and its fine. Even checked out with a multimeter.

But heres the weird part. 100.3 and 101.9 buzz on ignition, but 105.1 stays clear. WHAT THE?! Aerial earth is fine, and 2 out of 3 stations (only ones I listen to) buzz ONLY when the key is switched to ignition. CD's and AUX in is fine.

What gives?

[Luke0011]

As a quick reply could be a number of things but i guess your thinking its the unit. Easiest and fastest way would be to temporarily wire up another head unit if you have access to one to see if thats the cause. Did your previous unit have the same problem?

I would probably charge a 45 dollar fee to do this for you, i have a car audio workshop in the eastern suburbs if your interested.

[Fonzie]

First thing I'd check is the earth wire from the stereo... What do you mean only when the key is switched to ignition? The radio should be off if the key isn't on ignition

[azzfox]

Diddnt have a previous head unit (bought the car without one). But I do have a few old head units lying around which the current wiring harness is from one of them so would be a plug and play test.

Yeah only when key is switched to ignition. Theres accessories, ignition and start. Isnt a problem on accessories, only ignition for some reason. Head unit is earthed to bare metal. It could be a fault within the unit but why only on ignition and engine not even running? Doesnt make sense lol. Might have to open it up and inspect the earth tracks for main earth and antenna earth.

Cheers for the replies.