AM Radio Noise - '97 3.0 CL
09-21-2005, 07:32 AM
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AM Radio Noise - '97 3.0 CL
Hi All - Hope someone can help me with an ongoing radio problem in my '97 Acura 3.0 CL (original Acura Bose CD stereo, no CD changer, cassette player or other add-ons). On AM stations only, there is an electrical static/whine noise when the engine is running, and also when the key is turned only to the "on" (# 2) position without starting the engine (which powers up the HVAC system, power windows, etc.). The noise is not present when the radio is used with the engine off and the key is in the "accessory" (#1) position. This problem started several years ago and has gotten worse lately. With weaker AM stations, they are unlistenable, and now, even local AM stations are beginning to have some static/whine in the background at all times.
The noise does not change at all with engine rpm, but instead appears to be related to the electrical system external to the engine. The noise can be repeatedly turned on and off by switching the key between the #1 (accessory) and #2 "on" positions with the engine off. It varies in pitch back and forth a little when the key is turned to the #2 "on" position (but without the engine running) as the various dashboard indicator lights blink through their various initial check functions. It also temporarily goes downward in pitch (for a split second, perhaps in response to electrical load) while the engine is running as various electrical components in the car are switched off and on (air conditioner, etc.)
With the engine running one time about a year ago, the dealer temporarily unplugged the alternator cable and the radio noise completely stopped. I thought the solution was a bad alternator (which had itself been replaced a year earlier), but the dealer wouldn't say - it could also have been part of a related (alternator "priming" (?)) system. Now, the dealer reversed course and replaced the alternator (fortunately at their cost), but the noise is unexpectedly still there.
The dealer now says there is nothing they can do but refer me to a local car stereo shop that I visited once before at their recommendation. Basically, for several hundred dollars up front, they would tear apart my electrical system to see what's causing the noise. I'm a little wary of doing that, not to mention the cost. Does the car has any specific electrical noise suppressors that might need to be checked? Could anyone recommend any simple tests to diagnose the source?
If it is any help, I had a similar problem with my '87 Integra years ago, which was corrected completely by dealer installation of grounding straps on the car's rear wheels, guided at the time by an Acura service bulletin. However, since this problem seems to be getting gradually worse over time, maybe some kind of noise suppressor in the electrical system of the car (or in the radio itself) is wearing out.
This problem totally sucks during prime AM listening football season, so if anyone has any advice to offer based on these symptoms, I'd very much appreciate any assistance. Thanks in advance for your comments.
The noise does not change at all with engine rpm, but instead appears to be related to the electrical system external to the engine. The noise can be repeatedly turned on and off by switching the key between the #1 (accessory) and #2 "on" positions with the engine off. It varies in pitch back and forth a little when the key is turned to the #2 "on" position (but without the engine running) as the various dashboard indicator lights blink through their various initial check functions. It also temporarily goes downward in pitch (for a split second, perhaps in response to electrical load) while the engine is running as various electrical components in the car are switched off and on (air conditioner, etc.)
With the engine running one time about a year ago, the dealer temporarily unplugged the alternator cable and the radio noise completely stopped. I thought the solution was a bad alternator (which had itself been replaced a year earlier), but the dealer wouldn't say - it could also have been part of a related (alternator "priming" (?)) system. Now, the dealer reversed course and replaced the alternator (fortunately at their cost), but the noise is unexpectedly still there.
The dealer now says there is nothing they can do but refer me to a local car stereo shop that I visited once before at their recommendation. Basically, for several hundred dollars up front, they would tear apart my electrical system to see what's causing the noise. I'm a little wary of doing that, not to mention the cost. Does the car has any specific electrical noise suppressors that might need to be checked? Could anyone recommend any simple tests to diagnose the source?
If it is any help, I had a similar problem with my '87 Integra years ago, which was corrected completely by dealer installation of grounding straps on the car's rear wheels, guided at the time by an Acura service bulletin. However, since this problem seems to be getting gradually worse over time, maybe some kind of noise suppressor in the electrical system of the car (or in the radio itself) is wearing out.
This problem totally sucks during prime AM listening football season, so if anyone has any advice to offer based on these symptoms, I'd very much appreciate any assistance. Thanks in advance for your comments.
09-22-2005, 05:27 PM
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You Big Dummy
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I didn't know anyone actually listened to AM, much less liked it so much. J/K 
Seriously though, I really can't think of what it could be. My advise would be to post up on a real audio site.......if you haven't already. Good Luck.
Seriously though, I really can't think of what it could be. My advise would be to post up on a real audio site.......if you haven't already. Good Luck.
09-22-2005, 06:56 PM
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MalleusMaleficarum
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You'll need a ground loop isolator or something of the sort. Its just electrical interference. Maybe a burned or exposed wire could also be the culprit.