Intermittent high-pitched whine?

[Pete]

My '91 XLT has developed an intermittent high-pitched whine in the stereo. The whine comes and goes. It changes frequency with engine speed, i.e. as the engine revs the whine goes up and down in pitch. It also does it regardless of the stereo function, i.e. it doesn't matter whether it is on AM, FM, or CD.

The stereo is an aftermarket 35W Sony. The whine will suddenly appear while I'm driving along and then disappear a few minutes later or it may not disappear until later. It stops when the stereo is powered off. I'm thinking it's the fuel pump going south on me. Any ideas?

Thanks for your help!
Pete

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Pete

Thought for the day:
Good judgement comes from experience;
Experience comes from bad judgment.

 

[Chav]

Your problem is described as engine noise. This is a very common problem for those of us with amplifiers where noise can be introduced from the rca cables or a bad ground. You can go to Dead Link Removed
Good Luck

 

[JTang]

Do you have any aftermarket amps, or just the stock system with the new head unit?

I know people have posted things on the fuel pump and CB or Ham radios having interference. This might be the problem like you mentioned.

I had this exact problem before too, with a Sony head unit. It didn't happen with my Alpine, though. The Sony had a lot more power, that's the only thing I can think of, really. Perhaps try a better grounding point just for the head unit instead.