1999 BMW 740il causing major headache

These problems are all intermittent,cd player won`t turn on,tv has no volume,navigation has no volume,radio has no volume,when these items are faulty car battery goes flat in one night,when these work ok battery is perfect,new battery just fitted same problems,had wiring checked by bmw garage no faults found after 4 hours of looking,they say it might be the alternator,£900 on a might be is a big call,any ideas would be nice to hear,regards Colin(headache may turn to a migrane soon).

Colin I am by far no where near an expert but since I bought my 735 last month I have hit the forums hard :)
On many occasions the fault with random electrical gremlins is the ignition switch. look up ignition switch problems for the E38 on google.
Hope this helps
Si

Hi, I have the same issues and i have replaced the alternator alreadey. Now the redio acts up just like yours. I am looking to replace a computer module, i will let you know if it solves the problem.
Let me know if you have a cure for that problem
Tanks