# High-pitched sound when my lights are on

**URL:** <https://community.cartalk.com/t/high-pitched-sound-when-my-lights-are-on/28596>\
**Category:** Maintenance/Repairs\
**Tags:** noises, lights\
**Created:** [April 1, 2009, 2:48am UTC](https://community.cartalk.com/t/high-pitched-sound-when-my-lights-are-on/28596 "2009-04-01T02:48:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![LaurenH](https://avatars.discourse-cdn.com/v4/letter/l/ecae2f/32.png) [@LaurenH](https://community.cartalk.com/u/LaurenH)\
**Post date:** [April 1, 2009, 2:48am UTC](https://community.cartalk.com/t/high-pitched-sound-when-my-lights-are-on/28596/1 "2009-04-01T02:48:38Z")

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I was an idiot and left my lights on when I parked my car at the airport for four days. Of course my battery was dead and my battery was jumped (note the person who gave the car a jump reversed the polarity, quickly noticed and reversed his connections).  
  
  
  
 Now, when I turn on my headlights there is a nearly unbearable high pitch noise coming from what I think is the stereo system. The clock no longer works. The sound continues to blare if I then turn off my light, but I notice there is a change in the pitch when toggling the lights on and off. There does not seem to be a correlation between the sounds and whether the engine is running or not.  
  
  
  
 What can I do to fix this?  
  
  
  
 The car is an 1989 Toyota Corolla DX

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**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\
**Post date:** [April 1, 2009, 6:00am UTC](https://community.cartalk.com/t/high-pitched-sound-when-my-lights-are-on/28596/2 "2009-04-01T06:00:41Z")

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I would only speculate as to the exact electronic component that has been damaged but I do believe your car/electrical system has suffered damage from the reverse polarity incident.