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M5Wrexham

Speaker noise,aka engine rpm related

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Guys,

I have the engine rpm related whistle coming through all the speakers,background info as follows.

Full nav, BM54,amp,16:9 widescreen,Intravee & the KCA 420 I,I have upgraded the passenger side rear diversity amplifiers & added a secondary trap circuit on the drivers side,everything is well clamped & earthed,I have as a test run separate wires direct from the battery earth post to all individual components,but I still have this annoying noise,what other options do I have left,could this be a fecked BM54 module?

Thanks

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Hi

Symptoms like this is almost always a bad/not so good earth somewhere along the line. It's not recommended when installing audio components to use the battery terminal as the earth point, best practice is to always use another earthing point instead. As you've used the battery post, I'd suggest creating a good earth elsewhere and use that. 

 

Cheers, Dennis!

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Hi,

I used the battery earth post as a test point, if the noise had gone I would then know I had an earthing problem,unfortunately it didn't cure the issue,so I dont believe earthing points are an issue now,so I'm thinking bm54 is faulty

Thanks

Clayton

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Do you get noise on all sources?

 

Have you checked the condition of the engine earth strap and connections?  It only takes a minute resistance to create alternator noise.

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On 4/21/2016 at 5:23 PM, RichardP said:

Do you get noise on all sources?

 

Have you checked the condition of the engine earth strap and connections?  It only takes a minute resistance to create alternator noise.

Yes noises from all sources, even get the noise when the monitor is turned off, i already checked engine earth, i even individually earthed all the nav & modules in the boot, but no change at all.

Thanks

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Hi M5W,

 

Looks like it's more fault finding time, so do swap with a known working BM54 unit and swap it in and test. If the interference goes away, you'll know it's your unit that's faulty. If the noise persists, then you have electrical noise being picked up elsewhere. I don't know what you mean in the initial post about a 'trap unit', but remove that and the intravee and re-test. If the sounds persists, then perhaps somewhere along the loom, interference is being picked up, so you'll need to check that for continuity/placement etc. 

 

Hopefully, you'll be able to find the cause and fix it relatively easily !

 

Cheers, Dennis!

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It's possible it's a failing radio module or amp.  There may be internal corrosion or just dry joints that are causing an internal earthing problem.

 

What amp do you have, is it the Hi-Fi one (it will be unless you have DSP)?

 

I have a spare BM54 and Hi-Fi amp that you can borrow if you need them to swap out and eliminate possible causes. 

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13 hours ago, RichardP said:

It's possible it's a failing radio module or amp.  There may be internal corrosion or just dry joints that are causing an internal earthing problem.

 

What amp do you have, is it the Hi-Fi one (it will be unless you have DSP)?

 

I have a spare BM54 and Hi-Fi amp that you can borrow if you need them to swap out and eliminate possible causes. 

Hi Richard,

I have the std HiFi amp installed as i dont have DSP in the car, would be a real help if i could test your BM54 & amp as a process of elimination.

Will PM you

Thanks

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15 hours ago, DennisCooper said:

Hi M5W,

 

Looks like it's more fault finding time, so do swap with a known working BM54 unit and swap it in and test. If the interference goes away, you'll know it's your unit that's faulty. If the noise persists, then you have electrical noise being picked up elsewhere. I don't know what you mean in the initial post about a 'trap unit', but remove that and the intravee and re-test. If the sounds persists, then perhaps somewhere along the loom, interference is being picked up, so you'll need to check that for continuity/placement etc. 

 

Hopefully, you'll be able to find the cause and fix it relatively easily !

 

Cheers, Dennis!

Hi Dennis,

Its the small silver box in the pic.

Thanks

 

post-47686-14476685156155 (2).jpg

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Might be worth disconnecting the radio antenna just because it's easy and might be the cause of noise coming down the antenna shield.  I'd be supprised if it is, but worth a 30 second check.

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