Speaker whine (BM53)
 

When I bought my 3.0 E53 three months ago, the BM53 unit was faulty, only getting sound through one speaker, then it would cut out after about a minuet. After reading through numerous posts, sounds like a common problem. It had no speaker whine though.

I recently sent the BM53 unit out for repair, just received it back and re-fitted it, I'm now getting sound (music) through all speakers working like it should, but it seems to have developed another issue now-

High pitched whine which increases with the engine RPM's, happens with the head unit switched on or off (board monitor). If I disconnect the BM53 unit in the back, no more whine?

Not sure where to look first? Maybe something's not 100% with the BM53 repair, it only started since I refitted it after the repair.

Has anyone else experienced anything like this?

-BUMP-

Anyone experienced speaker whine with the stock stereo system?

I'm not sure of best approach in diagnosing this fault?

speaker whine is usually because something in the radio that was shielded has become unshielded. Speaker whine is typically caused by interference from the alternator which is why it increases and decreases depending on engine speed. I'd take it back to whoever did the recent work and let them know you didn't have THIS problem before they worked on it.

Thanks Fifty150hs for the reply, that pretty much explains it. The whine is driving me nuts!!

I've been working on cars for years, but I'm very much a novice when it comes to car audio, always stick with factory units.

The repair to the BM53 unit was carried out overseas- had to mail the unit, so wanted to be 100% sure that was the issue before retuning it.

I had a good look trough the whole car today, checked all the cables front to back (there is so much wiring in the back of these X5's!), checked the earths etc.

I removed the BM53 unit, and plugged in a single DIN aftermarket head unit via an adaptor at the BM53 harness connector- the whole system worked without issue- the whole factory harness/amp/speakers etc. No high pitched whine.

Plugged the BM53 back in, high pitch whine is back. There must be an earthing issue with the repair that was done?

I've emailed the repairer about returning under warranty to get sorted properly, so we'll see how we get on.

Hi, did you get the issue fixed? I have same issue with BM54 after repair.

After eliminating everything else in the system, it was the BM53.

I ended up sending it back to the repairer, they said they had opened it up and couldn't find anything that would be causing a whine. They did say it sometimes happens with the stage 2 repair, mine had the stage 1. Got it back with same issue.
I'm in New Zealand and it was repaired in the U.K. So wasn't a cheap exercise with postage backwards and forwards etc. Waste of time and money.

I ended up buying a known good unit off eBay U.S. for a decent price after keeping an eye out on there for a while.
Fitted it- works perfect now. I fitted an aux socket and couldn't be happier with it.

Wouldn't bother with a repair again.

How did you know it was a "known good unit" and can you advised me on what I should do? I also like you, had my BM54 repaired within the UK from a company called 'Cartronics' and I get the annoying whining sound even when the radio is turned off.

The BM53 was advertised as Fully working with all channels working without issue. Still a gamble as the seller can be B.S.ing, but it was cheap and worked out Ok.

The repair you had done will be guaranteed by that company, so if they are local you could returning with the complaint, let them know your not happy with it.
But to be honest, in my experience you might as well find a used good one. The repair involves some butchering to the PCB within the BM54 so not ideal really.

They are $$$ new, used they are still expensive for what they are, but you do see them come up on ebay cheap from time to time.
Its been a few years since I lived in the U.K. do you still have self service breakers yards like pick-a-part? might be worth keeping an eye out?

The good thing about the repair is that the sound quality is far superior than the stock version of the amp. If I just buy another unit online then i won't be happy with the sound quality. The alternator whine at the moment is drowned out by any music I play if the volume is high enough, but it is just annoying when there is no music playing.

Sorry to bring up this old thread. But does the OP still have the X5? Just want to know if your BM53 is alive and well and if it could read MP3 ID tags?

I have a 2003 4.6is with BM53 and recently installed an OEM 6 cd mp3 changer. The music plays fine but no song information is available.

I don't know if there's a firmware upgrade available to enable the id tag display or if we have to change to BM54?