# Static noise from radio

**URL:** <https://community.cartalk.com/t/static-noise-from-radio/39764>\
**Category:** Maintenance/Repairs\
**Tags:** outback, radio, subaru\
**Created:** [November 20, 2009, 6:39pm UTC](https://community.cartalk.com/t/static-noise-from-radio/39764 "2009-11-20T18:39:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![floydguy](https://avatars.discourse-cdn.com/v4/letter/f/c5a1d2/32.png) [@floydguy](https://community.cartalk.com/u/floydguy)\
**Post date:** [November 20, 2009, 6:39pm UTC](https://community.cartalk.com/t/static-noise-from-radio/39764/1 "2009-11-20T18:39:21Z")

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Car: 2004 Suburu Outback LL Bean Edition  
  
  
  
 Problem: radio emits strong static noise when car engine is on, but reception is clear when engine is off. Ongoing for \>year.  
  
  
  
 Original Radio: Alpine radio with retractable GPS  
  
  
  
 Actions to date: 1) Audio system examined twice by Suburu and Alpine mechanics, each claiming that the problem arose from the other’s domain. 2) Suburu replaced aerial pre-amplifier, but with no improvement. 3) Best Buy removed & upgraded old Alpine unit to Pioneer AVIC-U310BT 4.3 radio/GPS and replaced all wiring. Radio static problem remains while iPOD amplification is crystal clear and GPS works fine.  
  
  
  
 Please HELP

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**Author:** ![Triedaq](https://avatars.discourse-cdn.com/v4/letter/t/65b543/32.png) [@Triedaq](https://community.cartalk.com/u/Triedaq)\
**Post date:** [November 20, 2009, 8:24pm UTC](https://community.cartalk.com/t/static-noise-from-radio/39764/2 "2009-11-20T20:24:27Z")

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Two sources of this static are the ignition system and the alternator. There are suppressors on the ignition system as a spark transmits a signal across many frequency bands. Defective spark plug wires might be a cause. As far as the alternator is concerned, the slip rings may be generating interference. There also may be a bad diode and the alternator is superimposing alternating current on its direct current output.

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**Author:** ![floydguy](https://avatars.discourse-cdn.com/v4/letter/f/c5a1d2/32.png) [@floydguy](https://community.cartalk.com/u/floydguy)\
**Post date:** [November 21, 2009, 7:08pm UTC](https://community.cartalk.com/t/static-noise-from-radio/39764/3 "2009-11-21T19:08:17Z")

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Many thanks. I will go back to the Suburu mechanic with your diagnosis in hand and report back on the results.