BM amp relocation

swipe · Post by **swipe** » Fri Aug 12, 2011 6:43 pm

Guys has anyone moved their BM24 or BM54 amp from the standard location under the spare wheel, to the side pockets?
Only asking as my mrs 4.4 has has an LPG conversion with the dount tank in the place of the of the spare wheel, and I need to get the amp out as it keeps switching its self off.
Once I get the amp out I dont want to place in the orginal location in case of any other problems, not sure if on-one has done this so any help would be great.

AW8 · Post by **AW8** » Fri Aug 12, 2011 8:36 pm

For all the hassle I would get the amp changed or repaired, ( 2 traders on ebay can have a go for between Â£125 & Â£180 - 1 up north the other down south).

I say hassle because I think you would need to get a special extension adaptor made up or be very good at wiring as I doubt the cables would reach the cubby compartment(s).

Others may have had success but never heard of this being queried before.

Good Luck

Sanj · Post by **Sanj** » Fri Aug 12, 2011 8:45 pm

The loom won't stretch but if you get loads of wire and a soldering iron you can cut the wires and extend them...

swipe · Post by **swipe** » Fri Aug 12, 2011 9:12 pm

Cheers guys will look into it once the LPG tanks is empty

AW8 · Post by **AW8** » Fri Aug 12, 2011 11:16 pm

It goes almost without saying that you need to be sensible in offsetting any fire hazards near the LPG tank, especially from wiring issues.

Neil48is · Post by **Neil48is** » Sat Aug 13, 2011 7:20 am

I have a 4.8is on LPG and managed to move all of the electrics from under the spare wheel to the O/S cubby hole. I removed the DSP subs,but the wiring can be manipulated to reach the cubby quite easily without having to extend any wiring,i have the radio unit,TV Tuner,PDC and trailer module all in there. The only electrics left under the LPG tank is the battery.

swipe · Post by **swipe** » Sat Aug 13, 2011 10:06 am

Thanks guys really want this sorted as I love driving the mrs car. I have a diesel E class and miss the sound and power of the V8.

JimmySpeed · Post by **JimmySpeed** » Mon Aug 15, 2011 5:31 pm

If you have a bm24 you cab fix it yourself permanently in 10 mins. It shouldn't cut out again after that. If it's a bm54 I can't help you with that. The 24 is more than likely in need of a bit of resoldering which I found extremely easy and I am no electronics expert! 1 out 10 in difficulty.

Besides the battery is the thing most likely to be accessed (when your radio is fixed) and so I wouldn't worry about the rest. I can now move my LPG tank quicker than removing the spare and air pump gubbins once it's near empty. It's just a matter of doing it a few times although I have flexible pipes with plenty of length and easy mounting/demounting brackets for the tank. If your set up is different then it may be a complete pain in the backend to get it out.

swipe · Post by **swipe** » Mon Aug 15, 2011 9:01 pm

Got the bm24 amp out was a bit of a pain in the arse lifting the tank enough to gain access, gonna try and solder the joints even though they seem ok( no expert). Hopefully this will sort out the intermitant sound issue.

JimmySpeed · Post by **JimmySpeed** » Tue Aug 16, 2011 11:03 am

[quote=""swipe""]Got the bm24 amp out was a bit of a pain in the arse lifting the tank enough to gain access, gonna try and solder the joints even though they seem ok( no expert). Hopefully this will sort out the intermitant sound issue.[/quote]

I have just posted the following on a thread of someone having similar problems. The dry joints are not visible to the naked eye, apparently you can see them under a mag. glass though. Anyway I didn't bother checking, I just re-soldered. From what I have read it is extremely likely that this is the cause of your problem, and for such a cheap & easy fix its worth doing first.

For anyone else with BM24 problems, this is how I resolved mine:

It is a very easy fix, once you get the BM24 out, you will see torx bits holding on the casing. Basically, when the torx bits are out you can remove the casing and see the underside of the circuit board.

You will notice that there is a small circuit board (I have heard it referred to as a daughter board) attached vertically to the main circuit board and on the underside of the main board, you can see the solder where it is connected - There are 7 big blobs of solder in total in a horizontal line. They are grouped as follows: [single blob ------ 2 blobs together --------- 2 blobs together --------- 2 blobs together].

Here is a pic off the net showing exactly what I mean:

These blobs of solder will have become 'dry joints' meaning they will have cracked. You may or may not be able to see the cracks but its 99% certain that its happened and that is your problem.

I bought Argos' Â£3.99 soldering iron as it has a sharp fine tip, and then just some regular solder. All you need to do is heat the blobs until they become runny and then add in a touch of new solder to the joint once the existing solder is 'liquidey'. Do this on all 7 of the blobs (in fact where there are 2 together they are so close that they are almost like 1 big blob).

Once the solder is dry you will have better joints which shouldn't dry out again as the modern solder you have mixed in is more resistant to the lead free stuff they were using 10 years ago (i.e. when the BM24 was manufactured)

There are repair services on ebay that do this for Â£39.99 and even they admit that its cheap because its such an easy fix (not like the BM54).

swipe · Post by **swipe** » Tue Aug 16, 2011 8:47 pm

Thanks for the info Funny enough saw the pic and description the other day and that's what I was following. Have now done the resoldering and replaced the unit back in the the car, not been able to give it a good test yet. Even though I did have the stereo working and was shaking the hell out of the bm24 unit it seemed to work.
Really need a good few miles to give it a test, will try and run it on Thursday and report back, fingers crossed that it'll work.
Always said that the best place for advice was forum's like this thanks to all for the info!!!!

swipe · Post by **swipe** » Thu Aug 18, 2011 5:19 pm

Just an update the amp seems to running fine have done around 60 miles and the soldering might have done the trick. Will see in about a week how it all holds up.

JimmySpeed · Post by **JimmySpeed** » Thu Aug 18, 2011 8:24 pm

Fingers crossed you'll be okay. Mine has not even hiccuped since I soldered it and that was about a month ago now. It used to drop sound on every journey up to that.

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