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Russell H.
Russell H., Service Tech
Category: Car Electronics
Satisfied Customers: 9538
Experience:  8+ years of professional experience
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Jvc kd-r660 in a 77 mgb. radio works fine when car is not

Customer Question

jvc kd-r660 in a 77 mgb. radio works fine when car is not running but sounds like crap when car is running. replaced all grounds and posative cable but no luck.
Submitted: 1 year ago.
Category: Car Electronics
Expert:  Russell H. replied 1 year ago.
Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question. If the radio sounds noisy staticky and or with spikes, zaps and crackles, then a filter capacitor in the radio's interior has failed, which loses the filtering effect.But describe the problem with the sound to me, and I might be able to advise you in greater detail. (E.g. as to the size or approximate caliber of the capacitor that needs replacing.)And let me know whether the car radio is less than a year old, or covered by the car's warranty still... warranty repair would obviously be a good option if it can be done.
Customer: replied 1 year ago.
Yes it acts as you say. Just putchase the unit a couple days ago
Customer: replied 1 year ago.
Can a guy just add a capactor on the outside of the unit?
Expert:  Russell H. replied 1 year ago.
Yes, you could - if the connection is basically DC voltage, from the battery (and/or the alternator - a factor to realize, that it may produce spikes of higher voltage, so the rating of the capacitor has to have some 'extra' in it for the spikes, not just be rated to 15 V DC or the like... to be safest...) Be sure the polarity of the capacitor is correct of course, or the capacitor will soon explode, I've heard but never seen. At any rate, it's not good for it to be reversed against its polarity.Microfarads? possibly two, one a disc capacitor for the higher frequencies (and thus, higher sound pitches of noise), one an electrolytic for the lower frequencies. It depends upon how the static and/or other noise in the radio sounds, high-pitched or not-so-high-pitched.Suggested, vaguely appropriate numbers: rated to 30 to 50 V DC, the first capacitor about 10 to 75 microfarads, the second a 'disc' capacitor of about .01 to .05 microfarads. Good luck with it! If this completes the question as far as you're concerned, please rate my Answer - favorably I hope - so that I may be paid for the work I have done on your question. Thanks.

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